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Low Power IEEE 802.15.4 Zero-IF 2.4 GHz Transceiver IC ADF7241
FEATURES
Frequency range (global ISM band) 2400 MHz to 2483.5 MHz IEEE 802.15.4-2006-compatible (250 kbps) Low power consumption 19 mA (typical) in receive mode 21.5 mA (typical) in transmit mode (PO = 3 dBm) 1.7 A, 32 kHz crystal oscillator wake-up mode High sensitivity -95 dBm at 250 kbps Programmable output power -20 dBm to +4.8 dBm in 2 dB steps Integrated voltage regulators 1.8 V to 3.6 V input voltage range Excellent receiver selectivity and blocking resilience Zero-IF architecture Complies with EN300 440 Class 2, EN300 328, FCC CFR47 Part 15, ARIB STD-T66 Digital RSSI measurement Fast automatic VCO calibration Automatic RF synthesizer bandwidth optimization On-chip low power processor performs Radio control Packet management Packet management support Insertion/detection of preamble address/SFD/FCS IEEEE 802.15.4-2006 frame filtering IEEEE 802.15.4-2006 CSMA/CA unslotted modes Flexible 256-byte transmit/receive data buffer SPORT mode Flexible multiple RF port interface External PA/LNA support hardware Switched antenna diversity support Wake-up timer Very few external components Integrated PLL loop filter, receive/transmit switch, battery monitor, temperature sensor, 32 kHz RC and crystal oscillators Flexible SPI control interface with block read/write access Small form factor 5 mm x 5 mm 32-lead LFCSP package
APPLICATIONS
Wireless sensor networks Automatic meter reading/smart metering Industrial wireless control Healthcare Wireless audio/video Consumer electronics ZigBee
FUNCTIONAL BLOCK DIAGRAM
ADF7241
DAC LNA1 ADC DSSS DEMOD 8-BIT PROCESSOR 4kB PROGRAM ROM 2kB PROGRAM RAM 256-BYTE PACKET RAM 64-BYTE BBRAM 256-BYTE MCR PA FRACTIONAL-N RF SYNTHESIZER PRE-EMPHASIS FILTER WAKE-UP CTRL SPI GPIO SPORT IRQ
RADIO CONTROLLER
LNA2 ADC AGC OCL CDR PACKET MANAGER
DAC
LDO x 4
BIAS
Figure 1.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 (c)2011 Analog Devices, Inc. All rights reserved.
09322-001
BATTERY MONITOR
TEMPERATURE SENSOR
26MHz OSC
32kHz RC OSC
32kHz XTAL OSC
ADF7241 TABLE OF CONTENTS
Features .............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 General Description ......................................................................... 3 Specifications..................................................................................... 5 General Specifications ................................................................. 5 RF Frequency Synthesizer Specifications.................................. 5 Transmitter Specifications........................................................... 6 Receiver Specifications ................................................................ 6 Auxiliary Specifications ............................................................... 8 Current Consumption Specifications ........................................ 9 Timing and Digital Specifications.............................................. 9 Timing Diagrams........................................................................ 11 Absolute Maximum Ratings.......................................................... 15 ESD Caution................................................................................ 15 Pin Configuration and Function Descriptions........................... 16 Typical Performance Characteristics ........................................... 18 Terminology .................................................................................... 22 Radio Controller ............................................................................. 23 Sleep Modes................................................................................. 25 RF Frequency Synthesizer ............................................................. 26 RF Frequency Synthesizer Calibration .................................... 26 RF Frequency Synthesizer Bandwidth..................................... 27 RF Channel Frequency Programming..................................... 27 Reference Crystal Oscillator ..................................................... 27 Transmitter ...................................................................................... 28 Transmit Operating Modes ....................................................... 28 IEEE 802.15.4 Automatic RX-To-TX Turnaround Mode..... 30 Power Amplifier.......................................................................... 30 Receiver............................................................................................ 33 Receive Operation ...................................................................... 33 Receiver Calibration................................................................... 33 Receive Timing and Control ....................................................... 35 Clear Channel Assessment (CCA) ........................................... 36 Link Quality Indication (LQI) .................................................. 36 Automatic TX-to-RX Turnaround Mode ............................... 37 IEEE 802.15.4 Frame Filtering, Automatic Acknowledge, and Automatic CSMA/CA................................................................ 37 Receiver Radio Blocks ............................................................... 39 SPORT Interface ............................................................................. 40 SPORT Mode .............................................................................. 40 Device Configuration .................................................................... 41 Configuration Values ................................................................. 41 RF Port Configurations/Antenna Diversity................................ 42 Auxillary Functions........................................................................ 43 Temperture Sensor ..................................................................... 43 Battery Monitor .......................................................................... 43 Wake-Up Controller (WUC).................................................... 43 Transmit Test Modes.................................................................. 44 Serial Peripheral interface (SPI) ................................................... 45 General Characteristics ............................................................. 45 Command Access....................................................................... 45 Status Word ................................................................................. 45 Memory Map .................................................................................. 47 BBRAM........................................................................................ 47 Modem Configuration RAM (MCR) ...................................... 47 Program ROM ............................................................................ 47 Program RAM ............................................................................ 47 Packet RAM ................................................................................ 47 Memory Access............................................................................... 49 Writing to the ADF7241............................................................ 50 Reading from the ADF7241...................................................... 50 Downloadable Firmware Modules............................................... 53 Interrupt Controller ....................................................................... 54 Configuration ............................................................................. 54 Description of Interrupt Sources ............................................. 55 Applications Circuits...................................................................... 56 Register Map ................................................................................... 60 Outline Dimensions ....................................................................... 71 Ordering Guide .......................................................................... 71
REVISION HISTORY
1/11--Revision 0: Initial Version
Rev. 0 | Page 2 of 72
ADF7241 GENERAL DESCRIPTION
The ADF7241 is a highly integrated, low power, and high performance transceiver for operation in the global 2.4 GHz ISM band. It is designed with emphasis on flexibility, robustness, ease of use, and low current consumption. The IC supports the IEEE 802.15.42006 2.4 GHz PHY requirements in both packet and data streaming modes. With a minimum number of external components, it achieves compliance with the FCC CFR47 Part 15, ETSI EN 300 440 (Equipment Class 2), ETSI EN 300 328 (FHSS, DR > 250 kbps), and ARIB STD T-66 standards. The ADF7241 complies with the IEEE 802.15.4-2006 2.4 GHz PHY requirements with a fixed data rate of 250 kbps and DSSSOQPSK modulation. The transmitter path of the ADF7241 is based on a direct closed-loop VCO modulation scheme using a low noise fractional-N RF frequency synthesizer. The automatically calibrated VCO operates at twice the fundamental frequency to reduce spurious emissions and avoid PA pulling effects. The bandwidth of the RF frequency synthesizer is automatically optimized for transmit and receive operations to achieve best phase noise, modulation quality, and synthesizer settling time performance. The transmitter output power is programmable from -20 dBm to +4 dBm with automatic PA ramping to meet transient spurious specifications. An integrated biasing and control circuit is available in the IC to significantly simplify the interface to external PAs. The receive path is based on a zero-IF architecture enabling very high blocking resilience and selectivity performance, which are critical performance metrics in interference dominated environments such as the 2.4 GHz band. In addition, the architecture does not suffer from any degradation of blocker rejection in the image channel, which is typically found in low IF receivers. The IC can operate with a supply voltage between 1.8 V and 3.6 V with very low power consumption in receive and transmit modes while maintaining its excellent RF performance, making it especially suitable for battery-powered systems. The ADF7241 features a flexible dual-port RF interface that can be used with an external LNA and/or PA in addition to supporting switched antenna diversity. The ADF7241 incorporates a very low power custom 8-bit processor that supports a number of transceiver management functions. These functions are handled by the two main modules of the processor: the radio controller and the packet manager. The radio controller manages the state of the IC in various operating modes and configurations. The host MCU can use single byte commands to interface to the radio controller. In transmit mode, the packet manager can be configured to add preamble and SFD to the payload data stored in the on-chip packet RAM. In receive mode, the packet manager can detect and generate an interrupt to the MCU upon receiving a valid SFD, and store the received data payload in the packet RAM. A total of 256 bytes of transmit and receive packet RAM space is provided to decouple the over-the-air data rate from the host MCU processing speed. Thus, the ADF7241 packet manager eases the processing burden on the host MCU and saves the overall system power consumption. In addition, for applications that require data streaming, a synchronous bidirectional serial port (SPORT) provides bitlevel input/output data, and has been designed to directly interface to a wide range of DSPs, such as ADSP-21xx, SHARC(R), TigerSHARC(R), and Blackfin(R). The SPORT interface can optionally be used. The processor also permits the download and execution of a set of firmware modules, which include IEEE 802.15.4 automatic modes, such as node address filtering, as well as unslotted CSMA/CA. Execution code for these firmware modules is available from Analog Devices, Inc. To further optimize the system power consumption, the ADF7241 features an integrated low power 32 kHz RC wake-up oscillator, which is calibrated from the 26 MHz crystal oscillator while the transceiver is active. Alternatively, an integrated 32 kHz crystal oscillator can be used as a wake-up timer for applications requiring very accurate wake-up timing. A battery backed-up RAM (BBRAM) is available on the IC where IEEE 802.15.42006 network node addresses can be retained when the IC is in the sleep state. The ADF7241 also features a very flexible interrupt controller, which provides MAC-level and PHY-level interrupts to the host MCU. The IC is equipped with a SPI interface, which allows burst mode data transfer for high data throughput efficiency. The IC also integrates a temperature sensor with digital readback and a battery monitor.
Rev. 0 | Page 3 of 72
ADF7241
ADF7241
RFIO1P LNA1 RFIO1N RFIO2P LNA2 RFIO2N DAC ADC AGC OCL CDR PACKET MANAGER ADC DSSS DEMOD RADIO CONTROLLER DAC 8-BIT PROCESSOR 4kB PROGRAM ROM 2kB PROGRAM RAM 256- BYTE PACKET RAM 64-BYTE BBRAM 256-BYTE MCR PA DIV2 DIVIDER SDM PRE-EMPHASIS FILTER DSSS MOD SPI PABIAOP_ATB4 PAVSUP_ATB3 EXT PA INTERFACE CHARGEPUMP LOOP FILTER PFD CS MOSI SCLK MISO RXEN_GP6 TXEN_GP5
WAKE-UP CTRL
EXT LNA/PA ENABLE GPIO
PA RAMP
BATTERY MONITOR
TEMPERATURE SENSOR
ANALOG TEST 26MHz OSC
TIMER UNIT SPORT RC CAL 32kHz RC OSC 32kHz XTAL OSC
TRCLK_CKO_GP3 DT_GP1 DR_GP0 IRQ1_GP4 IRQ2_TRFS_GP2
LDO1
LDO2
LDO3
LDO4
BIAS
IRQ
Figure 2. Detailed Functional Block Diagram
Rev. 0 | Page 4 of 72
09322-011
CREGRF1, CREGVCO CREGSYNTH CREGDIG1, RBIAS XOSC26P CREGRF2, CREGDIG2 CREGRF3
XOSC26N
XOSC32KN_ATB2
XOSC32KP_GP7_ATB1
ADF7241 SPECIFICATIONS
VDD_BAT = 1.8 V to 3.6 V, GND = 0 V, TA = TMIN to TMAX, unless otherwise noted. Typical specifications are at VDD_BAT = 3.6 V, TA = 25C, fCHANNEL = 2450 MHz. All measurements are performed using the ADF7241 reference design, RFIO2 port, unless otherwise noted.
GENERAL SPECIFICATIONS
Table 1.
Parameter GENERAL PARAMETERS Voltage Supply Range VDD_BAT Input Frequency Range Operating Temperature Range Data Rate Min Typ Max Unit Test Conditions
1.8 2400 -40 250
3.6 2483.5 +85
V MHz C kbps
RF FREQUENCY SYNTHESIZER SPECIFICATIONS
Table 2.
Parameter CHANNEL FREQUENCY RESOLUTION PHASE ERROR Min Typ 10 3 1.5 VCO CALIBRATION TIME SYNTHESIZER SETTLING TIME 52 Max Unit kHz Degrees Degrees s Test Conditions Receive mode; integration bandwidth from 10 kHz to 400 kHz Transmit mode; integration bandwidth from 10 kHz to 1800 kHz Applies to all modes Frequency synthesizer settled to <5 ppm of the target frequency within this time following a VCO calibration Receive mode Transmit mode Receive mode 10 MHz frequency offset 50 MHz frequency offset Receive mode; fCHANNEL = 2405 MHz, 2450 MHz, and 2480 MHz Receive mode; measured at 400 kHz offset from fCHANNEL = 2405 MHz, 2418 MHz, 2431 MHz, 2444 MHz, 2457 MHz, 2470 MHz Parallel load resonant crystal
53 80 PHASE NOISE -135 -145 70 60
s s dBc/Hz dBc/Hz dBc dBc
REFERENCE AND CLOCK-RELATED SPURIOUS INTEGER BOUNDARY SPURS
CRYSTAL OSCILLATOR Crystal Frequency Maximum Parallel Load Capacitance Minimum Parallel Load Capacitance Maximum Crystal ESR Sleep-to-Idle Wake-Up Time
26 18 7 365.3 300
MHz pF pF s
Guarantees maximum crystal frequency error of 0.2 ppm; 33 pF on XOSC26P and XOSC26N 15 pF load on XOSC26N and XOSC26P
Rev. 0 | Page 5 of 72
ADF7241
TRANSMITTER SPECIFICATIONS
Table 3.
Parameter TRANSMITTER SPECIFICATIONS Maximum Transmit Power Minimum Transmit Power Maximum Transmit Power (High Power Mode) Minimum Transmit Power (High Power Mode) Transmit Power Variation Min Typ 3 -25 4.8 -22 2 Max Unit dBm dBm dBm dBm dB Transmit power = 3 dBm, fCHANNEL = 2400 MHz to 2483.5 MHz, TA = -40C to +85C, VDD_BAT = 1.8 V to 3.6 V Transmit power = 3 dBm For maximum transmit power = 3 dBm Test Conditions
Refer to Power Amplifier section for details on how to enable this mode
Transmit Power Control Resolution Optimum PA Matching Impedance Harmonics and Spurious Emissions Compliance with ETSI EN 300 440 25 MHz to 30 MHz 30 MHz to 1 GHz 47 MHz to 74 MHz, 87.5 MHz to 118 MHz, 174 MHz to 230 MHz, 470 MHz to 862 MHz Otherwise Above 1 GHz Compliance with ETSI EN 300 328 1800 MHz to 1900 MHz 5150 MHz to 5300 MHz Compliance with FCC CFR47, Part15 4.5 GHz to 5.15 GHz 7.25 GHz to 7.75 GHz Transmit EVM Transmit EVM Variation Transmit PSD Mask Transmit 20 dB Bandwidth
1
2 43.7 + 35.2j
dB
-36 -36 -54
dBm dBm dBm
Unmodulated carrier, 10 kHz RBW 1 Unmodulated carrier, 100 kHz RBW1 Unmodulated carrier, 100 kHz RBW1
-30 -47 -97 -41 -41 2 1 -56 2252
dBm dBm dBm/Hz dBm dBm % % dBm MHz
Unmodulated carrier, 1 MHz RBW1 Unmodulated carrier
1 MHz RBW1 1 MHz RBW1 Measured using Rohde & Schwarz FSU vector analyzer with ZigbeeTM option fCHANNEL = 2405 MHz to 2480 MHz, TA= -40C to +85C, VDD_BAT = 1.8 V to 3.6 V RBW = 100 kHz; |f - fCHANNEL| > 3.5 MHz
RBW = resolution bandwidth.
RECEIVER SPECIFICATIONS
Table 4.
Parameter GENERAL RECEIVER SPECIFICATIONS RF Front-End LNA and Mixer IIP3 Min Typ -13.6 -12.6 Max Unit dBm dBm Test Conditions At maximum gain, fBLOCKER1 = 5 MHz, fBLOCKER2 = 10.1 MHz, PRF,IN = -35 dBm At maximum gain, fBLOCKER1 = 20 MHz, fBLOCKER2 = 40.1 MHz, PRF,IN = -35 dBm At maximum gain, fBLOCKER1 = 40 MHz, fBLOCKER2 = 80.1 MHz, PRF,IN = -35 dBm
-10.5
dBm
Rev. 0 | Page 6 of 72
ADF7241
Parameter RF Front-End LNA and Mixer IIP2 RF Front-End LNA and Mixer 1 dB Compression Point Receiver LO Level at RFIO2 Port LNA Input Impedance at RFIO1x Port LNA Input Impedance at RFIO2x Port Receive Spurious Emissions Compliant with EN 300 440 30 MHz to 1000 MHz 1 GHz to 12.75 GHz RECEIVE PATH IEEE 802.15.4-2006 MODE Sensitivity (Prf,in,min, IEEE 802.15.4) Min Typ 24.7 -20.5 -100 50.2 - 52.2j 74.3 - 10.7j Max Unit dBm dBm dBm Test Conditions At maximum gain, fBLOCKER1 = 5 MHz, fBLOCKER2 = 5.5 MHz, PRF,IN = -50 dBm At maximum gain IEEE 802.15.4 packet mode Measured in RX state Measured in RX state
-57 -47 -95
dBm dBm dBm 1% PER with PSDU length of 20 bytes according to the IEEE 802.15.4-2006 standard 1% PER with PSDU length of 20 bytes PRF,IN = PRF,IN,MIN, IEEE 802.15.4 + 3 dB
Saturation Level CW Blocker Rejection 5 MHz 10 MHz 20 MHz 30 MHz Modulated Blocker Rejection 5 MHz 10 MHz 15 MHz 20 MHz 30 MHz Co-Channel Rejection Out-of Band Blocker Rejection -5 MHz -10 MHz -20 MHz -30 MHz -60 MHz
-15 55 60 63 64 48 61 62.5 65 65 -6
dBm dB dB dB dB
PRF,IN = PRF,IN,MIN, IEEE 802.15.4 + 3 dB dB dB dB dB dB dB
PRF,IN = PRF,IN,MIN + 10 dB modulated blocker PRF,IN = PRF,IN,MIN, IEEE 802.15.4 + 3 dB, measured at fCHANNEL = 2405 MHz
-34.2 -30.7 -29.7 -25.7 -24.2
dBm dBm dBm dBm dBm PRF,IN = PRF,IN,MIN, IEEE 802.15.4 + 3 dB, measured at fCHANNEL = 2480 MHz
+5 MHz +10 MHz +20 MHz +30 MHz +60 MHz Receiver Channel Bandwidth Frequency Error Tolerance RSSI Dynamic range Accuracy Averaging Time Minimum Sensitivity -80
-33.4 -29.9 -28.2 -23.7 -29.9 2252 +80
dBm dBm dBm dBm dBm kHz ppm
Two-sided bandwidth; cascaded analog and digital channel filtering PRF,IN = PRF,IN,MIN + 3 dB Measured using IEEE 802.15.4-2006 packet mode
85 3 128 -95
dB dB s dBm
Rev. 0 | Page 7 of 72
ADF7241
AUXILIARY SPECIFICATIONS
Table 5.
Parameter 32 kHz RC OSCILLATOR Frequency Frequency Accuracy Frequency Drift Temperature Coefficient Voltage Coefficient Calibration Time 32 kHz CRYSTAL OSCILLATOR Frequency Maximum ESR Start-Up Time WAKE-UP TIMER Prescaler Tick Period Wake-Up Period TEMPERATURE SENSOR Range Resolution Accuracy Min Typ 32.768 1 0.14 4 1 32.768 319.8 2000 Max Unit kHz % %/C %/V ms kHz k ms Test Conditions After calibration After calibration at 25C
10 pF on XOSC32KP and XOSC32KN 12.5 pF load capacitors on XOSC32KP and XOSC32KN
0.0305 61 x 10-6 -40 4.7 6.4
20,000 1.31 x 105 +85
ms sec C C C
Average of 1000 ADC readbacks, after using linear fitting, with correction at known temperature
BATTERY MONITOR Trigger Voltage Trigger Voltage Step Size Start-Up Time Current Consumption EXTERNAL PA INTERFACE RON, PAVSUP_ATB3 to VDD_BAT ROFF, PAVSUP_ATB3 to GND ROFF, PABIASOP_ATB4 to GND PABIASOP_ATB4 Source Current, Maximum PABIASOP_ATB4 Sink Current, Minimum PABIASOP_ATB4 Current Control Resolution PABIASOP_ATB4 Compliance Voltage PABIASOP_ATB4 Compliance Voltage Servo Loop Bias Current Servo Loop Bias Current Control Step
1.7 62 5 30 5 10 10 80 -80 6 150 3.45 22 0.349
3.6
V mV s A M M A A Bits mV V mA mA extpa_bias_mode = 0, 1, 2, 5, 6 extpa_bias_mode = 3, 4, power-down extpa_bias_mode = 0, power-down expta_bias_mode = 1, 3 extpa_bias_mode = 2, 4 extpa_bias_mode = 1, 2, 3, 4, 5 extpa_bias_mode = 2, 4 extpa_bias_mode = 1, 3 extpa_bias_mode = 5, 6 extpa_bias_mode = 5, 6
Rev. 0 | Page 8 of 72
ADF7241
CURRENT CONSUMPTION SPECIFICATIONS
Table 6.
Parameter CURRENT CONSUMPTION TX Mode Current Consumption -20 dBm -10 dBm 0 dBm +3 dBm +4 dBm Idle Mode PHY_RDY Mode RX Mode Current Consumption MEAS State SLEEP_BBRAM SLEEP_BBRAM_RCO SLEEP_BBRAM_XTO Min Typ Max Unit Test Conditions
16.5 17.4 19.6 21.5 25 1.8 10 19 3 0.3 1 1.7
mA mA mA mA mA mA mA mA mA A A A
IEEE 802.15.4-2006 continuous packet transmission mode IEEE 802.15.4-2006 continuous packet transmission mode IEEE 802.15.4-2006 continuous packet transmission mode IEEE 802.15.4-2006 continuous packet transmission mode IEEE 802.15.4-2006 continuous packet transmission mode XTO26M + digital active IEEE 802.15.4-2006 packet mode BBRAM contents retained 32 kHz RC oscillator running, some BBRAM contents retained, wake-up time enabled 32 kHz crystal oscillator running, some BBRAM contents retained, wake-up time enabled
TIMING AND DIGITAL SPECIFICATIONS
Table 7. Logic Levels
Parameter LOGIC INPUTS Input High Voltage, VINH Input Low Voltage, VINL Input Current, IINH/IINL Input Capacitance, CIN LOGIC OUTPUTS Output High Voltage, VOH Output Low Voltage, VOL Output Rise/Fall Output Load Min 0.7 x VDD_BAT 0.2 x VDD 1 10 VDD_BAT - 0.4 0.4 5 7 Typ Max Unit V V A pF V V ns pF IOH = 500 A IOL = 500 A Test Conditions
Table 8. GPIOs
Parameter GPIO OUTPUTS Output Drive Level Output Drive Level Min Typ 5 5 Max Unit mA mA Test Conditions All GPIOs in logic high state All GPIOs in logic low state
Table 9. SPI Interface Timing
Parameter t1 t2 t3 t4 t5 t6 t7 t8 Min 40 40 40 80 10 5 5 Typ Max 15 Unit ns ns ns ns ns ns ns ns Description CS falling edge to MISO setup time (TRX active) CS to SCLK setup time SCLK high time SCLK low time SCLK period SCLK falling edge to MISO delay MOSI to SCLK rising edge setup time MOSI to SCLK rising edge hold time
Rev. 0 | Page 9 of 72
ADF7241
Parameter t9 t10 t11 t12 t13 t14 t15, t16 Min 40 10 270 Typ Max Unit ns ns ns s ns ns ms Description SCLK to CS hold time CS high to SCLK wait time CS high time CS low to MISO high wake-up time, 26 MHz crystal with 10 pF load capacitance, TA = 25C SCLK rise time SCLK fall time CS high time on wake-up after RC_RESET or RC_SLEEP command (see Figure 5 and Figure 31) 26 MHz crystal with 10 pF load
300
400 20 20
2
Table 10. IEEE 802.15.4 State Transition Timing
Parameter Idle to PHY_RDY State PHY_RDY to Idle State PHY_RDY or TX to RX State (Different Channel) PHY_RDY or RX to TX State (Different Channel) PHY_RDY or TX to RX State (Same Channel) RX or PHY_RDY to TX State (Same Channel) RX Channel Change TX Channel Change TX to PHY_RDY State PHY_RDY to CCA State CCA to PHY_RDY State RX to Idle State TX to Idle State Idle to MEAS State MEAS to Idle State CCA to Idle State RX to CCA State CCA to RX State Min Typ 142 13.5 192 192 140 140 192 192 23 192 14.5 5.5 30.5 19 6 14.5 18 205 Max Unit s s s s s s s s s s s s s s s s s s Test Conditions
VCO calibration performed VCO calibration performed VCO calibration skipped VCO calibration skipped VCO calibration performed VCO calibration performed
Table 11. Timing IEEE 802.15.4-2006 SPORT Mode
Parameter t21 t22 t23 t24 t35 t36 t37 Min 18 0.51 16 1.3 14 10 6.2 Typ 2 Max Unit s s s s s s s Test Conditions/Comments SFD detect to TRCLK_CKO_GP3 (data bit clock) active delay TRCLK_CKO_GP3 bit period DR_GP0 to TRCLK_CKO_GP3 falling edge setup time TRCLK_CKO_GP3 symbol burst period PA nominal power to TRCLK_CKO_GP3 activity/entry into TX state RC_PHY_RDY to TRCLK_CKO_GP3 off RC_PHY_RDY to PA power shutdown
Table 12. MAC Timing
Parameter t26 t27 t28 tRX_MAC_DELAY 192 Min Typ 38 Max 150 150 Unit s s s s Test Conditions/Comments Time from frame received to rx_pkt_rcvd interrupt generation Time allowed, from issuing a RC_TX command, to update Register delaycfg2, Bit mac_delay_ext (0x10B[7:0]) Time allowed, from issuing a RC_TX command, to cancel the RC_TX command IEEE 802.15.4 mode as defined by the standard
Rev. 0 | Page 10 of 72
ADF7241
TIMING DIAGRAMS
SPI Interface Timing Diagram
CS
t11 t2
SCLK
t3
t4
t5
t9 t10
t1
MISO BIT 7
t6
BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 BIT 7 BIT 0 X BIT 7
t7
MOSI 7
t8
09322-002
6
5
4
3
2
1
0
7
7
Figure 3. SPI Interface Timing
Additional description and timing diagrams are available in the Serial Peripheral interface section.
Sleep-to-Idle SPI Timing Diagrams
CS
t9
SCLK 7 6 5 4 3 2 1 0
t12
MISO
t1
X
Figure 4. Sleep-to-Idle State Timing
t16
CS
SPI COMMAND TO ADF7242
RC_RESET OR RC_SLEEP
DEVICE STATUS
IDLE, PHY_RDY, RX
SLEEP
IDLE
Figure 5. Wake-Up After an RC_RESET or RC_SLEEP Command
Rev. 0 | Page 11 of 72
09322-064
09322-003
t6
ADF7241
MAC Delay Timing Diagram
PACKET TRANSMITTED PACKET RECEIVED FRAME IN TX_BUFFER
VALID IEEE802.15.4-2006 FRAME
RC_STATUS
RX tx_mac_delay + mac_delay_ext
TX
PHY_RDY
t26
REGISTER irq_src0, FIELD rc_ready REGISTER irq_src1, FIELD rx_pkt_rcvd REGISTER irq_src1, FIELD tx_pkt_sent
t27,t28
Figure 6. IEEE 802.15.4 MAC Timing
Rev. 0 | Page 12 of 72
09322-016
ADF7241
IEEE 802.15.4 RX SPORT Mode Timing Diagrams
Table 13. IEEE 802.15.4 RX SPORT Modes Configurations
Register rc_cfg, Field rc_mode (0x13E[7:0]) 2 0 Register gp_cfg, Field gpio_config (0x32C[7:0]) 1 7 Functionality Bit clock and data available (see Figure 7) Symbol clock and data available (see Figure 8)
COMMAND RC_STATUS
RC_RX PREVIOUS STATE
RC_PHY_RDY
RX
PHY_RDY
tRX_MAC_DELAY
PREAMBLE SFD PHR PSDU
t29
t21
TRCLK_CKO_GP3
t21
t24
DR_GP0
.....
DATA INVALID
TRCLK_CKO_GP3 .....
..... .....
DR_GP0 .....
t22
Figure 7. IEEE 802.15.4 RX SPORT Mode: Bit Clock and Data Available
COMMAND RC_STATUS
RC_RX PREVIOUS STATE
RC_PHY_RDY
RX
PHY_RDY
tRX_MAC_DELAY
PREAMBLE SFD PHR PSDU
t29
t21
TRCLK_CKO_GP3
t26
t21
GP6, GP5, GP1, GP01
1GP6 = RXEN_GP6
SYMBOL
[3:0] [3:0] [3:0] [3:0]
[3:0] [3:0] [3:0] [3:0]
Figure 8. IEEE 802.15.4 RX SPORT Mode: Symbol Clock Output
Rev. 0 | Page 13 of 72
09322-009
GP5 = TXEN_GP5 GP1 = DT_GP1 GP0 = DR_GP0
09322-004
t23
ADF7241
IEEE 802.15.4 TX SPORT Mode Timing Diagram
Table 14. IEE 802.15.4 TX SPORT Mode Configurations
Register rc_cfg, Field rc_mode (0x13E[7:0]) 3 Register gp_cfg, Field gpio_config (0x32C[7:0]) 1 or 4 Functionality Transmission starts after PA ramp up (see Figure 9) gpio_config = 1: data clocked in on rising edge of clock gpio_config = 4: data clocked in on falling edge of clock
RC_TX
RC_PHY_RDY
RC STATE
PHY_RDY
TX
PHY_RDY
PA POWER
t37 t35
PACKET COMPONENT
PREAMBLE
SFD
PHR
PSDU
t36
TRCLK_CKO_GP3
.....
PACKET DATA
DT_GP1
.....
REGISTER gp_cfg, FIELD gpio_config = 1 DATA CLOCKED IN ON RISING EDGE
REGISTER gp_cfg, FIELD gpio_config = 4 DATA CLOCKED IN ON FALLING EDGE
t32
TRCLK_CKO_GP3 DT_GP1 SAMPLE TRCLK_CKO_GP3 DT_GP1 SAMPLE
t32
DT_GP1
DT_GP1
t33
t34
t33
t34
Figure 9. IEEE 802.15.4-2006 TX SPORT Mode
Refer to the SPORT Interface section for further details.
Rev. 0 | Page 14 of 72
09322-122
ADF7241 ABSOLUTE MAXIMUM RATINGS
TA = 25C, unless otherwise noted. Table 15.
Parameter VDD_BAT to GND Operating Temperature Range Industrial Storage Temperature Range Maximum Junction Temperature LFCSP JA Thermal Impedance Reflow Soldering Peak Temperature Time at Peak Temperature Rating -0.3 V to +3.9 V -40C to +85C -65C to +125C 150C 26C/W 260C 40 sec
The exposed paddle of the LFCSP package should be connected to ground. This device is a high performance RF integrated circuit with an ESD rating of <2 kV, and it is ESD sensitive. Proper precautions should be taken for handling and assembly.
ESD CAUTION
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Rev. 0 | Page 15 of 72
ADF7241 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
PABIAOP_ATB4 PAVSUP_ATB3 VDD_BAT XOSC32KN_ATB2 XOSC32KP_GP7_ATB1 CREGDIG1 RXEN_GP6 TXEN_GP5 32 31 30 29 28 27 26 25
CREGRF1 RBIAS CREGRF2 RFIO1P RFIO1N RFIO2P RFIO2N CREGRF3
1 2 3 4 5 6 7 8
ADF7241
TOP VIEW (Not to Scale)
24 23 22 21 20 19 18 17
CS MOSI SCLK MISO IRQ1_GP4 TRCLK_CKO_GP3 IRQ2_TRFS_GP2 DT_GP1
CREGVCO VCOGUARD CREGSYNTH XOSC26P XOSC26N DGUARD CREGDIG2 DR_GP0
9 10 11 12 13 14 15 16
NOTES 1. THE EXPOSED PADDLE MUST BE CONNECTED TO GROUND.
Figure 10. Pin Configuration
Table 16. Pin Function Descriptions
Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Mnemonic CREGRF1 RBIAS CREGRF2 RFIO1P RFIO1N RFIO2P RFIO2N CREGRF3 CREGVCO VCOGUARD CREGSYNTH XOSC26P XOSC26N DGUARD CREGDIG2 DR_GP0 DT_GP1 IRQ2_TRFS_GP2 TRCLK_CKO_GP3 IRQ1_GP4 MISO SCLK MOSI CS TXEN_GP5 RXEN_GP6 CREGDIG1 XOSC32KP_GP7_ATB1 XOSC32KN_ATB2 Description Regulated Supply Terminal for RF Section. Connect a 220 nF decoupling capacitor from this pin to GND. Bias Resistor 27 k to Ground. Regulated Supply for RF Section. Connect a 100 pF decoupling capacitor to ground. Differential RF Input Port 1 (Positive Terminal). A 10 nF coupling capacitor is required. Differential RF Input Port 1 (Negative Terminal). A 10 nF coupling capacitor is required. Differential RF Input/Output Port 2 (Positive Terminal). A 10 nF coupling capacitor required. Differential RF Input/Output Port 2 (Negative Terminal). A 10 nF coupling capacitor required. Regulated Supply for RF Section. Connect a 100 pF decoupling capacitor from this pin to GND. Regulated Supply for VCO Section. Connect a 220 nF decoupling capacitor from this pin to GND. Guard Trench for VCO Section. Connect to Pin 9 (CREGVCO). Regulated Supply for PLL Section. Connect a 220 nF decoupling capacitor from this pin to GND. Terminal 1 of External Crystal and Loading Capacitor. This pin is no connect (NC) when an external oscillator is used. Terminal 2 of External Crystal and Loading Capacitor. Input for external oscillator. Guard Trench for Digital Section. Connect to Pin 15 (CREGDIG2). Regulated Supply for Digital Section. Connect a 220 nF decoupling capacitor to ground. SPORT Receive Data Output/General-Purpose IO Port. SPORT Transmit Data Input/General-Purpose IO Port. Interrupt Request Output 2/IEEE 802.15.4-2006 Symbol Clock/General-Purpose IO Port. SPORT Clock Output/General-Purpose IO Port. Interrupt Request Output 1/General-Purpose IO Port. SPI Interface Serial Data Output. SPI Interface Data Clock Input. SPI Interface Serial Data Input. SPI Interface Chip Select Input (and Wake-Up Signal). External PA Enable Signal/General-Purpose IO Port. External LNA Enable Signal/General-Purpose IO Port. Regulated Supply for Digital Section. Connect a 1 nF decoupling capacitor from this pin to ground. Terminal 1 of 32 kHz Crystal Oscillator/General-Purpose IO Port/Analog Test Bus 1. Terminal 2 of 32 kHz Crystal Oscillator/Analog Test Bus 2.
Rev. 0 | Page 16 of 72
09322-010
ADF7241
Pin No. 30 31 32 33 (EPAD) Mnemonic VDD_BAT PAVSUP_ATB3 PABIAOP_ATB4 GND Description Unregulated Supply Input from Battery. External PA Supply Terminal/Analog Test Bus 3. External PA Bias Voltage Output/Analog Test Bus 4. Common Ground Terminal. The exposed paddle must be connected to ground.
Rev. 0 | Page 17 of 72
ADF7241 TYPICAL PERFORMANCE CHARACTERISTICS
2.0 1.8 1.6 PACKET ERROR RATE (%) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 -90 -93 -80 -70 -60 -50 -40 RF INPUT POWER LEVEL (dBm) -30 -20
09322-095
80
REJECTION LEVEL (dB)
2.405GHz, 1.8V, +25C 2.48GHz, 1.8V, +25C 2.405GHz, 3.6V, +25C 2.48GHz, 3.6V, +25C 2.405GHz, 1.8V, -40C 2.48GHz, 1.8V, -40C 2.405GHz, 3.6V, -40C 2.48GHz, 3.6V, -40C 2.405GHz, 1.8V, +85C 2.48GHz, 1.8V, +85C 2.405GHz, 3.6V, +85C 2.48GHz, 3.6V, +85C
70 60 50 40 30 20 10 0 1.8V, 3.6V, 1.8V, 3.6V, 1.8V, 3.6V, +25C +25C -40C -40C +85C +85C
09322-048 09322-050
0 -100 -96
-10 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 BLOCKER FREQUENCY OFFSET (MHz)
Figure 11. IEEE 802.15.4-2006 Packet Mode Sensitivity vs. Temperature and VDD_BAT, fCHANNEL = 2.405 GHz, 2.45 GHz, 2.48 GHz, RFIO2x
2.0 1.8 1.6
PACKET ERROR RATE (%)
Figure 14. IEEE 802.15.4-2006 Packet Mode Blocker Rejection vs. Temperature and VDD_BAT, Modulated Blocker, PWANTED = -85 dBm + 3 dB, fCHANNEL = 2.45 GHz, RFIO2x
80
BLOCKER REJECTION LEVEL (dB)
1.4 1.2 1.0 0.8 0.6 0.4 0.2 -90 -80 -70 -60 -50 -40 RF INPUT POWER LEVEL (dBm)
3.6V, +25C 1.8V, +25C 3.6V, -40C 1.8V, -40C 3.6V, +85C 1.8V, +85C
70 60 50 40 30 20 10 0 -10 VDD_BAT = 3.6V TEMPERATURE = 25C -70 -50 -30 -10 10 50 70 BLOCKER FREQUENCY OFFSET (MHz) 90 110
09322-049
-30
-20
-96.5 -95
09322-046
0 -100
-20 -110 -90
Figure 12. IEEE 802.15.4-2006 Packet Mode PER vs. RF Input Power Level vs. Temperature and VDD_BAT, fCHANNEL = 2.45 GHz, RFIO2x
2.0 1.8 1.6
PACKET ERROR RATE (%)
Figure 15. IEEE 802.15.4-2006 Packet Mode Wide-Band Blocker Rejection, CW Blocker, PWANTED = -95 dBm + 3 dB, fCHANNEL = 2.45 GHz, RFIO2x
80
1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 -100
2.405GHz, 2.450GHz, 2.475GHz, 2.405GHz, 2.450GHz, 2.475GHz, 2.405GHz, 2.450GHz, 2.475GHz, 2.405GHz, 2.450GHz, 2.475GHz, 2.405GHz, 2.450GHz, 2.475GHz, 2.405GHz, 2.450GHz, 2.475GHz, -98 -96 -96
1.8V, 1.8V, 1.8V, 3.6V, 3.6V, 3.6V, 1.8V, 1.8V, 1.8V, 3.6V, 3.6V, 3.6V, 1.8V, 1.8V, 1.8V, 3.6V, 3.6V, 3.6V,
+25C +25C +25C +25C +25C +25C -40C -40C -40C -40C -40C -40C +85C +85C +85C +85C +85C +85C
09322-047
70
BLOCKER REJECTION LEVEL (dB)
60 50 40 30 20 10 0 -10 -20 -20 VDD_BAT = 3.6V TEMPERATURE = 25C -16 -12 -8 -4 0 4 8 12 BLOCKER FREQUENCY OFFSET (MHz) 16 20
-94 -92 -90 -88 -86 -84 -82 -93 RF INPUT POWER LEVEL (dBm)
-80
Figure 13. IEEE 802.15.4 Packet Mode Sensitivity vs. Temperature and VDD_BAT, fCHANNEL = 2.405 GHz, 2.45 GHz, 2.475 GHz, RFIO1x
Figure 16. IEEE 802.15.4 Packet Mode Narrow-Band Blocker Rejection, CW Blocker, PWANTED = -95 dBm + 3 dB, fCHANNEL = 2.45 GHz, RFIO2x
Rev. 0 | Page 18 of 72
ADF7241
80 70
BLOCKER REJECTION LEVEL (dB)
6 5 4 MAX 1.8V, +25C MIN 1.8V, +25C MAX 3.6V, +25C MIN 3.6V, +25C MAX 1.8V, -40C MIN 1.8V, -40C MAX 3.6V, -40C MIN 3.6V, -40C
60 50 40 30 20 10 0 1.8V, 3.6V, 1.8V, 3.6V, 1.8V, 3.6V, +25C +25C -40C -40C +85C +85C
09322-099
3
RSSI ERROR (dB)
2 1 0 -1 -2 -3 -4 -5 MAX 1.8V, +85C MIN 1.8V, +85C MAX 3.6V, +85C MIN 3.6V, +85C
09322-112
-10 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 BLOCKER FREQUENCY OFFSET (MHz)
-6 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -30 -25 -20 RF INPUT LEVEL (dBm)
Figure 17. IEEE 802.15.4 Packet Mode Wide-Band Blocker Rejection vs. Temperature and VDD_BAT, Modulated Blocker, PWANTED = -95 dBm + 3 dB, fCHANNEL = 2.45 GHz, RFIO2x
80 70 60
Figure 20. IEEE 802.15.4 Packet Mode RSSI Error vs. RF Input Power Level vs. Temperature and VDD_BAT, fCHANNEL = 2.45 GHz, RFIO2x
275 250 225
REJECTION LEVEL (dB)
50 40 30 20 10 0 -10 -20 1.8V, 3.6V, 1.8V, 3.6V, 1.8V, 3.6V, -16 +25C +25C -40C -40C +85C +85C
09322-100
SQI READBACK VALUE
200 175 150 125 100 75 50 25 MAX 1.8V, MAX 3.6V, MAX 1.8V, MAX 3.6V, MAX 1.8V, MAX 3.6V, +25C +25C -40C -40C +85C +85C MIN 1.8V, MIN 3.6V, MIN 1.8V, MIN 3.6V, MIN 1.8V, MIN 3.6V, +25C +25C -40C -40C +85C +85C
-12 -8 -4 0 4 8 12 INTERFERER FREQUENCY OFFSET (MHz)
16
20
Figure 18. IEEE 802.15.4 Packet Mode Narrow-Band Blocker Rejection vs. Temperature and VDD_BAT, Modulated Blocker, PWANTED = -95 dBm + 3 dB, fCHANNEL = 2.45 GHz, RFIO2x
-20 -22 -24 -26 -28 -30 -32 -34 CHANNEL 2.405GHz CHANNEL 2.48GHz
Figure 21. IEEE 802.15.4 Packet Mode SQI vs. RF Input Power Level vs. Temperature and VDD_BAT, fCHANNEL = 2.45 GHz, RFIO2x
110 THRESHOLD = 100 90 -80 dBm -70 dBm -60 dBm -50 dBm -40 dBm -30 dBm -20 dBm
BLOCKER REJECTION LEVEL (dBm)
CCA DETECTION RATE (%)
80 70 60 50 40 30 20 10 -90 dBm
09322-101
-70 -50 -30 -10 10 30 50 70 BLOCKER FREQUENCY OFFSET (MHz)
90
110
Figure 19. IEEE 802.15.4 Packet Mode Out-of-Band Blocker Rejection, CW Blocker, PWANTED = -95 dBm + 3 dB, fCHANNEL = 2.405 GHz and 2.48 GHz, RFIO2x, VDD_BAT = 3.6 V, Temperature = 25C
Figure 22. IEEE 802.15.4-2006 CCA Operation vs. RSSI Threshold, fCHANNEL = 2.45 GHz, VDD_BAT = 3.6 V, Temperature = 25C, RFIO2x
Rev. 0 | Page 19 of 72
09322-114
-36 -110 -90
0 -90 -85 -80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -30 -25 -20 -15 RF INPUT POWER LEVEL (dBm)
09322-113
0 -100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -30 -25 -20 RF INPUT LEVEL (dBm)
ADF7241
0
TRANSMITTER RF OUTPUT POWER (dBm)
4
1.8V, 3.6V, 1.8V, 3.6V, 1.8V, 3.6V, +25C +25C -40C -40C +85C +85C
PA OUTPUT POWER LEVEL (dBm)
-10
2 0 -2 -4 -6 -8 -10 -12 -14 -16 -18 -20 -22 -24 -26 -28 3 4 5 6 7 8 9 10 11 PA LEVEL SETTING 3.6V, 3.6V, 3.6V, 1.8V, 1.8V, 1.8V, 12 +85C +25C -40C -40C +25C +80C 14 15
09322-111
-20 -30
-40
-50
-60 -70 -5
-4
-3
-2
-1
0
1
2
3
4
5
09322-104
13
FREQUENCY ERROR (kHz)
Figure 23. IEEE 802.15.4-2006 Transmitter Spectrum vs. Temperature and VDD_BAT, fCHANNEL = 2.45 GHz, Output Power = 3 dBm
Figure 26. PA Output Power vs. Control Word, Temperature, and VDD_BAT, fCHANNEL = 2.44 GHz (A discrete matching network and a harmonic filter are used as per the ADF7241 reference design.)
5.0
TRANSMITTER OUTPUT POWER (dBm)
TRANSMITTER ERROR VECTOR MAGNITUDE (%)
2.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1
09322-105
EVM 1.8V, EVM 3.6V, EVM 1.8V, EVM 3.6V, EVM 1.8V, EVM 3.6V,
+25C +25C -40C -40C +85C +85C
2.5 0 -2.5 -5.0 -7.5 -10.0 -12.5 -15.0 -17.5 -20.0 -22.5 -25.0 HIGH POWER MODE DEFAULT MODE
09322-119
1.0 2405
-27.5 3 4 5 6 7 8 9 10 11 12 13 14 POWER AMPLIFIER CONTROL WORD 15 16
2415
2425
2435
2445
2455
2465
2475
CHANNEL FREQUENCY (MHz)
Figure 24. IEEE 802.15.4-2006 Transmitter EVM vs. Temperature and VDD_BAT at All Channels, Output Power = 3 dBm
Figure 27. Transmitter Output Power vs. Control Word for Default and High Power Modes, fCHANNEL = 2.45 GHz, VDD_BAT = 3.6 V, Temperature = 25C, RF Carrier Frequency, Temperature, and VDD_BAT (A discrete matching network and a harmonic filter are used as per the ADF7241 reference design.)
26.0 25.5 25.0 24.5 24.0 23.5 23.0 22.5 22.0 21.5 21.0 20.5 20.0 19.5 19.0 18.5 18.0 17.5 17.0 16.5 16.0
TRANSMITTER CURRENT CONSUMPTION (mA)
4.0 3.5
PA OUTPUT POWER LEVEL (dBm)
HIGH POWER MODE DEFAULT MODE
3.0 2.5 2.0 1.5 1.0 0.5 0 2.40 3.6V, 3.6V, 3.6V, 1.8V, 1.8V, 1.8V, 2.41 2.42 2.43 2.44 2.45 FREQUENCY (GHz) 2.46 +85C +25C -40C -40C +25C +80C
09322-110
2.47
2.48
3
4
5
6 7 8 9 10 11 12 13 POWER AMPLIFIER CONTROL WORD
14
15
Figure 25. PA Output Power vs. RF Carrier Frequency, Temperature, and VDD_BAT (A discrete matching network and a harmonic filter are used as per the ADF7241 reference design.)
Figure 28. Transmitter Current Consumption vs. Control Word, for Default and High Power Modes, fCHANNEL = 2.45 GHz, VDD_BAT = 3.6 V, Temperature = 25C
Rev. 0 | Page 20 of 72
09322-120
ADF7241
85 3-SIGMA TEMPERATURE ERROR 80 75 TEMPERATURE READING (LINEAR FITTING) 70 TEMPERATURE READING 65 (POLYNOMIAL FITTING) 60 55 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 -40 -40 -30 -20 -10 0 10 20 30 40 50 60 TEMPERATURE (C)
TEMPERATURE CALCULATED FROM ADC READING (C)
70
80
Figure 29. Temperature Sensor Performance (Average of 1000 ADC Readbacks) and 3- Error vs. Temperature, VDD_BAT = 3.6 V
09322-116
Rev. 0 | Page 21 of 72
ADF7241 TERMINOLOGY
ACK IEEE 802.15.4-2006 acknowledgment frame ADC Analog-to-digital converter AGC Automatic gain control Battmon Battery monitor CCA Clear channel assessment BBRAM Backup battery random access memory CSMA/CA Carrier-sense-multiple-access with collision avoidance DR Data rate DSSS Direct sequence spread spectrum FCS Frame check sequence FHSS Frequency hopping spread spectrum FCF Frame control field LQI Link quality indicator MCR Modem configuration register MCU Microcontroller unit NC Not connected OCL Offset correction loop OQPSK Offset-quadrature phase shift keying PA Power amplifier PHR PHY header PHY Physical layer POR Power-on reset PSDU PHY service data unit RC Radio controller RCO32K 32 kHz RC oscillator RSSI Receive signal strength indicator RTC Real-time clock SFD Start-of-frame delimiter SQI Signal quality indicator VCO Voltage-controlled oscillator WUC Wake-up controller XTO26M 26 MHz crystal oscillator XTO32K 32 kHz crystal oscillator
Rev. 0 | Page 22 of 72
ADF7241 RADIO CONTROLLER
COLD START (BATTERY APPLIED) CONFIGURE DEVICE FIRMWARE DOWNLOAD FOR EXAMPLE, IEEE 802.15.4 AUTO-MODES WUC TIMEOUT RC_MEAS MEAS RC_IDLE IDLE RC_SLEEP CS SLEEP
RC_PHY_RDY
RC_IDLE
RC_SLEEP (FROM ANY STATE)
E DL _I RC
RC_RESET (FROM ANY STATE)
CCA COMPLETE RC_PHY_RDY PHY_RDY RC_CCA
A CC CO
CCA
PL M
RC _P HY _R RC DY _R X
RC _P HY _R DY RC _T X
A _CC RC
ET E
RX RC_
1
E CK PA
TT
T MIT NS RA
ED
RC_TX RC_RX
PA CK ET RE CE IVE 1 D
TX RC_TX AUTO_RX_TO_TX_TURNAROUND 2
RX RC_RX
AUTO_TX_TO_RX_TURNAROUND 2
1AVAILABLE 2THESE
IN PACKET MODE. TRANSITIONS ARE CONFIGURED IN BUFFERCFG (0x107[3:2]).
KEY STATE TRANSITION INITIATED BY HOST MCU
09322-024
AUTOMATIC STATE TRANSITION INITIATED BY RADIO CONTROLLER RADIO STATE
Figure 30. State Diagram
Rev. 0 | Page 23 of 72
RC _ID L
L _ID RC E
E
ADF7241
The ADF7241 incorporates a radio controller that manages the state of the IC in various operating modes and configurations. The host MCU can use single-byte commands to interface to the radio controller. The function of the radio controller includes the control of the sequence of powering up and powering down various blocks as well as system calibrations in different states of the device. Figure 30 shows the state diagram of the ADF7241 with possible transitions that are initiated by the host MCU and automatically by the radio controller. The PHY_RDY state can be entered from the idle, RX, TX, or CCA state by issuing an RC_PHY_RDY command.
RX State
The RF frequency synthesizer is automatically calibrated to the programmed channel frequency upon entering the RX state from the PHY_RDY or TX state. The frequency synthesizer calibration can be omitted for single-channel communication systems if short turnaround times are required. Following a programmable MAC delay period, the ADF7241 starts searching for a preamble and a synchronization word if enabled by the user. The RX state can be entered from the PHY_RDY, CCA, and TX states by issuing an RC_RX command. Depending on whether the device is configured to operate in packet or SPORT mode by setting Register buffercfg, Field rx_buffer_mode, the device can revert automatically to the PHY_RDY state when a packet is received, or remain in the RX state until a command to enter a different state is issued. Refer to the Receiver section for further details.
Device Initialization
When the battery voltage is first applied to the ADF7241, a cold start-up sequence should be followed, as shown in Figure 31. The start-up sequence is as follows: * Apply the battery voltage, VDD_BAT, to the device with the desired voltage ramp rate. After a time, tRAMP, VDD_BAT reaches its final voltage value. After tRAMP, execute the SPI command, RC_RESET. This command resets and shuts down the device. After the specified time, t15, the host MCU can set the CS port of the SPI low. Wait until the MISO output of the SPI (SPI_READY flag) goes high, at which time the device is in the idle state and ready to accept commands.
* * *
CCA State
Upon entering the CCA state, a clear channel assessment is performed. The CCA state can be entered from the PHY_RDY or RX state by issuing an RC_CCA command. By default, upon completion of the clear channel assessment, the ADF7241 automatically reverts to the state from which the RC_CCA command originated.
A power-on reset takes place when the host MCU sets the CS port of the SPI low. All device LDOs are enabled together with the 26 MHz crystal oscillator and the digital core. After the radio controller initializes the configuration registers to their default values, the device enters the idle state. The cold start-up sequence is needed only when the battery voltage is first applied to the device. Afterwards, a warm startup sequence can be used where the host MCU can wake up the device from a sleep state by setting the CS port of the SPI low.
TX State
Upon entering the TX state, the RF frequency synthesizer is automatically calibrated to the programmed channel frequency. The frequency synthesizer calibration can be omitted for communication systems operating on a single channel if short turnaround times are required. Following a programmable delay period, the PA is ramped up and transmission is initiated. The TX state can be entered from the PHY_RDY or RX state by issuing the RC_TX command. Depending on whether the device is configured to operate in packet or SPORT mode by setting Register buffercfg, Field rx_buffer_mode, the device can revert automatically to the PHY_RDY state when a packet is transmitted, or remain in the TX state until a command to enter a different state is issued. Refer to the Transmitter section for further details.
Idle State
In this state, the receive and transmit blocks are powered down. The digital section is enabled and all configuration registers, as well as the packet RAM, are accessible. The host MCU must set any configuration parameters, such as modulation scheme, channel frequency, and WUC configuration, in this state. Bringing the CS input low in the sleep state causes a transition into the idle state. The transition from the sleep state to the idle state timing is shown in Figure 4. The idle state can also be entered by issuing an RC_IDLE command in any state other than the sleep state.
MEAS State
The MEAS state is used to measure the chip temperature. The transmitter and receiver blocks are not enabled in this state. The chip temperature is measured using the ADC, which can be read from Register adc_rbk, Field adc_out, and is continuously updated with the chip temperature reading. This state is enabled by issuing the RC_MEAS command from the idle state and can be exited using the RC_IDLE command.
PHY_RDY State
Upon entering the PHY_RDY state from the idle state, the RF frequency synthesizer is enabled and a system calibration is carried out. The receive and transmit blocks are not enabled in this state. The system calibration is omitted when the PHY_RDY state is entered from the RX, TX, or CCA state.
Rev. 0 | Page 24 of 72
ADF7241
Sleep States
The sleep state is entered with the RC_SLEEP command. The sleep state can be configured to operate in three different modes, which are listed in Table 17. Table 17. ADF7241 Sleep Modes
Sleep Mode SLEEP_BBRAM Active Circuits BBRAM Functionality Packet RAM and modem configuration register (MCR) contents are not maintained. BBRAM retains the IEEE 802.15.4-2006 node addresses1. 32 kHz crystal oscillator is enabled, with data retention in the BBRAM. 32 kHz RC oscillator is enabled, with data retention in the BBRAM.
SLEEP_BBRAM_XTO
This mode enables the 32 kHz crystal oscillator and retains certain configuration registers in the BBRAM during the sleep state. To enable SLEEP_BBRAM_XTO mode, set Register tmr_cfg1, Field sleep_config = 5. A wake-up interrupt can be set using, for example, Register irq1_en0, Field wakeup = 1. Refer to the Wake-Up Controller (WUC) section for details on how to configure the ADF7241 WUC.
SLEEP_BBRAM_RCO
This mode enables the 32 kHz RC oscillator and retains certain configuration registers in the BBRAM during the sleep state. This mode can be used when lower timer accuracy is acceptable by the communication system. It is enabled by setting Register tmr_cfg1, Field sleep_config = 11. A wake-up interrupt can be set using, for example, Register irq1_en0, Field wakeup = 1. Refer to the Wake-Up Controller (WUC) section for details on how to configure the ADF7241 WUC.
SLEEP_BBRAM_XTO
SLEEP_BBRAM_RCO
BBRAM and 32 kHz crystal oscillator BBRAM and 32 kHz RC Oscillator
Wake-Up from the Sleep State
The host MCU can bring CS low at any time to wake the ADF7241 from the sleep state. After bringing CS low, it must wait until the MISO output (SPI_READY flag) goes high prior to accessing the SPI port. This delay reflects the start-up time of the ADF7241. When the MISO output is high, the voltage regulator of the digital section and the crystal oscillator have stabilized. Unless the chip is in the sleep state, the MISO pin always goes high immediately after bringing CS low. The sleep state can also be exited by a timeout event with the WUC configured. Refer to the Wake-Up Controller (WUC) section for details on how to configure the ADF7241 WUC.
t15
1
Refer to the Receiver Configuration in Packet Mode section for further details.
SLEEP MODES
The sleep modes are configurable with the wake-up configuration registers, tmr_cfg0 and tmr_cfg1. The contents of Register tmr_cfg0 and Register tmr_cfg1 are reset in the sleep state.
SLEEP_BBRAM
This mode is suitable for applications where the MCU is equipped with its own wake-up timer. SLEEP_BBRAM mode is enabled by setting Register tmr_cfg1, Field sleep_config = 1.
APPLY VDD_BAT
CS
SPI COMMAND TO ADF7241
RC_RESET (0xC8)
IDLE
SLEEP
IDLE
Figure 31. Cold Start Sequence from Application of the Battery
Rev. 0 | Page 25 of 72
09322-063
DEVICE STATE
ADF7241 RF FREQUENCY SYNTHESIZER
A fully integrated RF frequency synthesizer is used to generate both the transmit signal and the receive LO signal. The architecture of the frequency synthesizer is shown in Figure 32. The receiver uses the frequency synthesizer circuit to generate the local oscillator (LO) for downconverting an RF signal to the baseband. The transmitter is based on a direct closed-loop VCO modulation scheme using a low noise fractional-N RF frequency synthesizer, where a high resolution - modulator is used to generate the required frequency deviations at the RF in response to the data being transmitted. The VCO and the frequency synthesizer loop filter of the ADF7241 are fully integrated. To reduce the effect of VCO pulling by the power-up of the power amplifier, as well as to minimize spurious emissions, the VCO operates at twice the RF frequency. The VCO signal is then divided by 2 giving the required frequency for the transmitter and the required LO frequency for the receiver. The frequency synthesizer also features automatic VCO calibration and bandwidth selection.
RX AND TX CIRCUITS CHANNEL SELECTION IN RX OR TX
used to mitigate the effect of temperature, supply voltage, and process variations on the VCO performance. The VCO calibration phase must not be skipped during the system calibration in the PHY_RDY state. Therefore, it is important to ensure that Register vco_cal_cfg, Field skip_vco_cal = 9 prior to entering the PHY_RDY state from the idle state. This is the default setting and, therefore, only requires programming if skipping of the calibration was previously selected. The VCO calibration can be skipped on the transition from the PHY_RDY state to the RX, TX, and CCA states on the condition that the calibration has been performed in the PHY_RDY state on the same channel frequency to be used in the RX, TX, and CCA states. The following sequence should be used if skipping the VCO calibration is required in any state following the PHY_RDY state: 1. After the system calibration is performed in the PHY_RDY state, the VCO frequency band in Register vco_band_rb, Field vco_band_val_rb and the VCO bias DAC code in Register vco_idac_rb, Field vco_idac_val_rb should be read back. Before transitioning to any other state and assuming operation on the same channel frequency, the VCO frequency band and amplitude DAC should be overwritten as follows: a) Set Register vco_cal_cfg, Field skip_vco_cal = 15 to skip the VCO calibration. b) Enable the VCO frequency over-write mode by setting Register vco_ovrw_cfg, Field vco_band_ovrw_en = 1. c) Write the VCO frequency band read back after the system calibration in the PHY_RDY state to Register vco_band_ovrw, Field vco_band_ovrw_val. d) Enable the VCO bias DAC over-write mode by setting Register vco_ovrw_cfg, Field vco_idac_ovrw_en = 1 e) Write the VCO bias DAC read back after the system calibration in the PHY_RDY state to Register vco_idac_ovrw, Field vco_idac_ovrw_val .
DIV2
N-DIVIDER
SDM
2.
CHARGE-PUMP AND LOOP FILTER
PFD
26MHz XOSC + DOUBLER
VCO CALIBRATION
Figure 32. Synthesizer Architecture
RF FREQUENCY SYNTHESIZER CALIBRATION
The ADF7241 requires a system calibration prior to being used in the RX, CCA, or TX state. Because the calibration information is reset when the ADF7241 enters a sleep state, a full system calibration is automatically performed on the transition between the idle and PHY_RDY states. The system calibration is omitted when the PHY_RDY state is entered from the TX, RX, or CCA state.
142s PWR Up RC Cal 24s 20s VCO Cal 52s SYNTHESIZER SETTLING 46s
09322-012
09322-089
AUTO SYNTH BANDWIDTH SELECTION
DO NOT SKIP, SET REGISTER vco_cal_cfg, FIELD skip_vco_cal = 9
Figure 33. System Calibration Following RC_PHY_RDY
Following the preceding procedure, the device can transition to other states, which use the same channel frequency without performing a VCO calibration. If it is required to change the channel frequency before entering the RX, TX, or CCA state at any point after the preceding procedure has been used, Register vco_ cal_cfg, Field skip_vco_cal must be set to 9 before transitioning to the respective state. Then the VCO calibration is automatically performed.
Figure 33 shows a breakdown of the total system calibration time. It comprises a power-up delay, calibration of the receiver baseband filter (RC Cal), and a VCO calibration (VCO Cal). Once the VCO is calibrated, the frequency synthesizer is allowed to settle to within 5 ppm of the target frequency. A fully automatic fast VCO frequency and amplitude calibration scheme is
Rev. 0 | Page 26 of 72
ADF7241
RF FREQUENCY SYNTHESIZER BANDWIDTH
The ADF7241 radio controller optimizes the RF frequency synthesizer bandwidth based on whether the device is in the RX or the TX state. If the device is in the RX state, the frequency synthesizer bandwidth is set by the radio controller to ensure optimum blocker rejection. If the device is in the TX state, the radio controller sets the frequency synthesizer bandwidth based on the required data rate to ensure optimum modulation quality.
REFERENCE CRYSTAL OSCILLATOR
The on-chip crystal oscillator generates the reference frequency for the frequency synthesizer and system timing. The oscillator operates at a frequency of 26 MHz. The crystal oscillator is amplitude controlled to ensure a fast start-up time and stable operation under different operating conditions. The crystal and associated external components should be chosen with care because the accuracy of the crystal oscillator can have a significant impact on the performance of the communication system. Apart from the accuracy and drift specification, it is important to consider the nominal loading capacitance of the crystal. Crystals with a high loading capacitance are less sensitive to frequency pulling due to tolerances of external capacitors and the printed circuit board parasitic capacitances. When selecting a crystal, these advantages should be balanced against the higher current consumption, longer start-up time, and lower trimming range resulting from a larger loading capacitance. The total loading capacitance must be equal to the specified load capacitance of the crystal and comprises the external parallel loading capacitors, the parasitic capacitances of the XOSC26P and XOSC26N pins, as well as the parasitic capacitance of tracks on the printed circuit board. The ADF7241 has an integrated crystal oscillator tuning capacitor that facilitates the compensation of systematic production tolerance and temperature drift. The tuning capacitor is controlled with Register xto26_trim _cal, Field xto26_trim (0x371). The tuning range provided by the tuning capacitor depends on the loading capacitance of a specific crystal. The total tuning range is typically 25 ppm.
RF CHANNEL FREQUENCY PROGRAMMING
The frequency of the synthesizer is programmed with the frequency control word, ch_freq[23:0], which extends over Register ch_freq0, Register ch_freq1, and Register ch_freq2. The frequency control word, ch_freq[23:0], contains a binary representation of the absolute frequency of the desired channel divided by 10 kHz. Writing a new channel frequency value to the frequency control word, ch_freq[23:0], takes effect after the next frequency synthesizer calibration phase. The frequency synthesizer is calibrated by default during the transition into the PHY_RDY from the idle state as well as in the TX, RX and CCA states. Refer to the RF Frequency Synthesizer Calibration, Transmitter, and Receiver sections for further details. To facilitate fast channel frequency changes, a new frequency control word can be written in the RX state before a packet has been received. The next RC_RX or RC_TX command initiates the required frequency synthesizer calibration and settling cycle. Similarly, a new frequency control word can be written after a packet has been transmitted while in the TX state and the next RC_RX or RC_TX command initiates the frequency synthesizer calibration and settling cycle.
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ADF7241 TRANSMITTER
TRANSMIT OPERATING MODES
The two primary transmitter operating modes are: * * IEEE 802.15.4-2006 packet mode IEEE 802.15.4-2006 SPORT mode appended to the frame in TX_BUFFER. In this case, the number of bytes written to TX_BUFFER must be equal to the length specified in the PHR field minus two. The format of the frame in TX_BUFFER, both with automatic FCS field generation enabled and with it disabled, is shown in Figure 34. Details of how to configure IEEE 802.15.4-2006 TX SPORT mode are given in the SPORT Interface section.
The desired mode of operation is selected via Register rc_cfg, Field rc_mode. The modulator preemphasis filter must be enabled with Register tx_m, Field preemp_filt = 1. This is enabled by default if using packet mode only, but must be programmed if using SPORT mode. IEEE 802.15.4-2006-compatible mode with packet manager support is selected with Register rc_cfg, Field rc_mode = 0 (0x13E). In this mode, the ADF7241 packet manager automatically generates the IEEE 802.15.4-2006-compatible preamble and SFD. There is also an option to use a nonstandard SFD by programming Register sfd_15_4 with the desired alternative SFD. Refer to the Programmable SFD subsection of the Receiver section for further details. There are 256 bytes of dedicated RAM (packet RAM), which constitute TX_BUFFER and RX_BUFFER, available to store transmit and receive packets. The packet header must be the first byte written to TX_BUFFER. The address of the first byte of TX_BUFFER is stored in Register txpb, Field tx_pkt_base. If the automatic FCS field generation has been disabled (Register pkt_cfg, Field auto_fcs_off = 1), the full frame including FCS must be written to TX_BUFFER. In this case, the number of bytes written to TX_BUFFER must be equal to the length specified in the PHR field. If automatic FCS field generation has been enabled (Register pkt_cfg, Field auto_fcs_off = 0), the FCS is automatically
1 2 1
IEEE 802.15.4-2006 Transmitter Timing and Control
This section applies when IEEE 802.15.4-2006 packet mode is enabled. Accurate control over the transmission slot timing is maintained by two delay timers (Register delaycfg1, Field tx_mac_delay and Register delaycfg2, Field mac_delay_ext), which introduce a controlled delay between the rising edge of the CS signal following the RC_TX command and the start of the transmit operation. Figure 35 illustrates the timing of the transmit operation assuming that the ADF7241 was operating in PHY_RDY, RX, or TX state prior to the execution of an RC_TX command. If enabled, the external PA interface, as described in the Power Amplifier section, is powered up prior to the synthesizer calibration to allow sufficient time for the bias servo loop to settle. Ramp-up of the PA is completed shortly before the overall MAC delay has elapsed. If enabled, an rc_ready interrupt (see the Interrupt Controller section) is generated at the transition into the TX state. Following the completion of the PA ramp-up phase, the transceiver enters the TX state. The minimum and maximum times for the PA ramp-up to complete prior to the transceiver entering the TX state are given by Parameter t35 in Table 11.
0 TO 20 ADDRESS INFORMATION n FRAME PAYLOAD 2
SEQ NUM
PHR
REGISTER pkt_cfg, FIELD auto_fcs_off = 1
REGISTER txpb, FIELD tx_pkt_base REGISTER rc_cfg, FIELD rc_mode = 0 1 2 1 0 TO 20 ADDRESS INFORMATION
REGISTER txpb, FIELD tx_pkt_base + 5 + (0 to 20) + n n FRAME PAYLOAD
REGISTER pkt_cfg, FIELD auto_fcs_off = 0
SEQ NUM
PHR
FCF
FCS
FCF
REGISTER txpb, FIELD tx_pkt_base
REGISTER txpb, FIELD tx_pkt_base + 5 + (0 to 20) + n - 2
Figure 34. Field Format of TX_BUFFER
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09322-015
ADF7241
EXTERNAL PA BIAS PA OUTPUT POWER TRANSMITTED PACKET RC_TX RC_STATUS PREVIOUS STATE tx_mac_delay + mac_delay_ext OPERATION SYNTH CALIBRATION REGISTER irq_src0, FIELD rc_ready
09322-013
PREAMBLE SFD PHR
PSDU
TX
PHY_RDY
REGISTER irq_src1, FIELD tx_sfd REGISTER irq_src1, FIELD tx_pkt_sent
Figure 35. Transmit Timing and Control
192s tx_mac_delay
0s TO 1020s mac_delay_ext
154s INIT 22s VCO_cal 52s SYNTHESIZER SETTLING 80s PA RAMP <6s
.............
PA RAMP <6s
09322-014
SKIPPED IF REGISTER vco_cal_cfg, FIELD skip_vco_cal = 15
Figure 36. Synthesizer Calibration Following RC_TX
The radio controller first transmits the automatically generated preamble and SFD. If it has been enabled, an SFD interrupt is asserted after the SFD is transmitted. The packet manager then reads TX_BUFFER, starting with the PHR byte and transmits its contents. Following the transmission of the entire frame, the radio controller turns the PA off and asserts a tx_pkt_sent interrupt. The ADF7241 then automatically returns to the PHY_RDY state unless automatic operating modes have been configured. By default, the synthesizer is recalibrated each time an RC_TX command is issued. Figure 36 shows the synthesizer calibration sequence that is performed each time the transceiver enters the TX state. The total TX MAC delay is defined by the combined delay configured with Register delaycfg1, Field tx_mac_delay and Register delaycfg2, Field mac_delay_ext. Register delaycfg1, Field tx_mac_delay is programmable in steps of 1 s, whereas Register delaycfg2, Field mac_delay_ext is programmable in steps of 4 s. The default value of Register delaycfg1, Field tx_mac_delay is the length of 12 IEEE 802.15.4-2006-2.4 GHz symbols or 192 s. The default value of Register delaycfg2, Field mac_delay_ext is 0 s. Following the issue of the RC_TX command, while the delay defined by Register delaycfg1, Field tx_mac_delay is elapsing, Register delaycfg2, Field mac_delay_ext can be
updated up until the time, t27, specified in Table 12. This allows a dynamic adjustment of the transmission timing for acknowledge (ACK) frames for networks using slotted CSMA/CA. To ensure correct settling of the synthesizer prior to PA ramp-up, the total TX MAC delay should not be programmed to a value shorter than specified by the PHY_RDY or RX to TX timing specified in Table 10. The RC_TX command can be aborted up to the time specified by Parameter t28 in Table 12 by means of issuing an RC_PHY_RDY, RC_RX, or RC_IDLE command. The VCO calibration (VCO_cal) can be skipped if shorter turnaround times are required. Skipping the VCO calibration is possible if the channel frequency control word ch_freq[23:0] has remained unchanged since the last RC_PHY_RDY, RC_RX, RC_CCA, or RC_TX command was issued with VCO_cal enabled. The initialization, synthesizer settling, and PA ramping phases are mandatory however because the synthesizer bandwidth is changed between receive and transmit operation. Skipping the VCO calibration is an option for single-channel communication systems, or systems where an ACK frame is transmitted on the same channel upon reception of a packet. VCO_cal is skipped by setting Register vco_cal_cfg, Field skip_vco_cal = 15. In this case, tx_mac_delay can be reduced to 140 s. The VCO calibration is executed if Register vco_cal_cfg, Field skip_vco_cal = 9.
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ADF7241
PACKET TRANSMITTED PACKET RECEIVED
FRAME IN TX_BUFFER
VALID IEEE802.15.4-2006 FRAME
RC_STATUS
RX tx_mac_delay + mac_delay_ext
TX
PHY_RDY
t26
REGISTER irq_src0, FIELD rc_ready REGISTER irq_src1, FIELD rx_pkt_rcvd REGISTER irq_src1, FIELD tx_pkt_sent
t27,t28
Figure 37. IEEE 802.15.4 Auto RX-to-TX Turnaround Mode
IEEE 802.15.4 AUTOMATIC RX-TO-TX TURNAROUND MODE
The ADF7241 features an automatic RX-to-TX turnaround mode when it is operating in IEEE 802.15.4-2006 packet mode (Register rc_cfg, Field rc_mode = 0). The automatic RX-to-TX turnaround mode facilitates the timely transmission of acknowledgment frames. Figure 37 illustrates the timing of the automatic RX-to-TX turnaround mode. When enabled by setting Register buffercfg, Field auto_rx_to_tx_turnaround, the ADF7241 automatically enters the TX state following the reception of a valid IEEE 802.15.4-2006 frame. After the combined transmit MAC delay (tx_mac_delay + mac_delay_ext), the ADF7241 enters the TX state and transmits the frame stored in TX_BUFFER. After the transmission is complete, the ADF7241 enters the PHY_RDY state. There is a 38 s delay between the reception of the last symbol and the generation of the rx_pkt_rcvd interrupt. The transmit MAC delay timeout period begins immediately after the reception of the last symbol. Therefore, the host MCU has up to t28 s (see Table 12) after a frame has been received to cancel the transmit operation by means of issuing an RC_IDLE, RC_PHY_RDY, or RC_RX command.
PA Ramping Controller
The PA ramping controller of the ADF7241 minimizes spectral splatter generated by the transmitter. Upon entering the TX state, the ramping controller automatically ramps the output power of the PA from the minimum output power to the specified nominal value. In packet mode, transmission of the packet commences after the ramping phase. When the transmission of the packet is complete or the TX state is exited, the PA is turned off immediately. It is also possible to allow the PA to ramp down its output power using the same ramp rate for the ramp-up phase, by setting Register ext_ctrl, Field pa_shutdown_mode to 1. Figure 38 illustrates the shape of the PA ramping profile and its timing. It follows a linear-in-dB shape. The ramp time depends on the output power setting in Register extpa_msc, Field pa_pwr and is specified with Register pa_rr, Field pa_ramp_rate according to the following equation: t_ramp = 2pa_rr.pa_ramp_rate x 2.4 ns x extpa_msc.pa_pwr
External PA Interface
The ADF7241 has an integrated biasing block for external PA circuits as shown in Figure 39. It is suitable for external PA circuits based on a single GaAs MOSFET and a wide range of integrated PA modules. The key components are shown in Figure 40. A switch between Pin VDD_BAT and Pin PAVSUP_ATB3 controls the supply current to the external FET. PABIOP_ATB4 can be used to set a bias point for the external FET. The bias point is controlled by a 5-bit DAC and/or a bias servo loop. To have the external PA interface under direct control of the host MCU, set Register ext_ctrl, Field extpa_auto_en = 0. The host MCU can then use Register pd_aux, Field extpa_bias_en to enable or disable the external PA. If Register ext_ctrl, Field extpa_auto_en = 1, the external PA automatically turns on when entering, and turns off when exiting the TX state. If this setting is used, the host MCU should not alter the configuration of Register pd_aux, Field extpa_bias_en.
POWER AMPLIFIER
The integrated power amplifier (PA) is connected to the RFIO2P and RFIO2N RF ports. It is equipped with a built-in harmonic filter to simplify the design of the external harmonic filter. The output power of the PA is set with Register extpa_msc, Field pa_pwr with an average step size of 2 dB. The step size increases at the lower end of the control range. Refer to Figure 26 for the typical variation of output power step size with the control word value. The PA also features a high power mode, which can be enabled by setting Register pa_bias, Field pa_bias_ctrl = 63 and Register pa_cfg, Field pa_bridge_dbias = 21.
Rev. 0 | Page 30 of 72
09322-121
ADF7241
The function of the two pins, PAVSUP_ATB3 and PABIAOP_ ATB4, depends on the mode selected with Register extpa_msc, Field extpa_bias_mode, as shown in Table 18. The reference current source for the DAC is controlled with Register extpa_msc, Field extpa_bias_src (0x3AA[3]). If Register extpa_msc, Field extpa_bias_src = 0, the current is
PA OUTPUT POWER
derived from the external bias resistor. If Register extpa_msc, Field extpa_bias_src = 1, the current is derived from the internal reference generator. The first option is more accurate and is recommended whenever possible.
pa_ramp_rate = 0: 20 x 2.4ns PER 2dB STEP RC_TX ISSUED 2dB
pa_ramp_rate = 7: 27 x 2.4ns PER 2dB STEP
TRANSMISSION OF PACKET COMPLETE OR LEAVING TX STATE
DATA TRANSMISSION ACTIVE
tx_mac_delay + mac_delay_ext
Figure 38. PA Ramping Profile
Rev. 0 | Page 31 of 72
09322-018
PO, MIN
t
ADF7241
External PA Interface Modes
* Mode 0 allows supply to an external circuit to be switched on or off. This is useful for circuits that have no dedicated power-down pin and/or have a high power-down current. Mode 1 allows the supply to an external circuit to be switched on or off. In addition, the PABIOP_ATB4 pin acts as a programmable current source. A programmable voltage can be generated if a suitable resistor is connected between PABIAOP_ATB4 and GND. Mode 2 allows the supply to an external PA circuit to be switched on or off. In addition, the PABIOP_ATB4 pin acts as a programmable current sink. A programmable voltage can be generated if a suitable resistor is connected between PABIAOP_ATB4 and VDD_BAT. Mode 3 is the same as Mode 1, except that the switch between PAVSUP_ATB3 and VDD_BAT is open. Mode 4 is the same as Mode 2, except that the switch between PAVSUP_ATB3 and VDD_BAT is open. Mode 5 is intended for a PA circuit based on a single external FET. The supply voltage to this FET is controlled through the PAVSUP_ATB3 pin to ensure a low leakage current in the power-down state. The bias servo loop controls the gate bias voltage of the external FET such that the current through the supply switch is equal to a reference current. The reference current for the bias servo loop is generated by the 5-bit reference DAC. In this mode, the bias servo loop expects the current in the FET to increase with increasing voltage at the PABIAOP_ATB4 output. Mode 6 is the same as Mode 5, except that the bias servo loop expects the current in the FET to increase with decreasing voltage at the PABIAOP_ATB4 output.
RFIO1P BALUN RFIO1N LNA
*
*
*
VDD_BAT PAVSUP_ATB3 PABIAOP_ATB4 EXTERNAL PA INTERFACE CIRCUIT
* * *
PA RFIO2P BALUN RFIO2N LNA
TXEN_GP5 GaAs pHEMT FET
09322-020
ADF7241
Figure 39. Typical External PA Applications Circuit
Table 18. PA Interface
Register extpa_msc, Field extpa_bias_mode X2 0 1 2 3 4 5 6 7
1 2
Register pd_aux, Field extpa_bias_en1 0 1 1 1 1 1 1 1 1
VDD_BAT to PAVSUP_ATB3 Switch Open Closed Closed Closed Open Open Closed Closed Reserved
Function of Pin PABIAOP_ATB4 Not used Not used Current source Current sink Current source Current sink Bias current servo output, positive polarity Bias current servo output, negative polarity Reserved
Autoenabled when Register ext_ctrl, Field extpa_auto_en = 1. X = don't care.
ADF7241
VDD_BAT SWITCH PAVSUP_ATB3
&
REGISTER ext_ctrl, FIELD extpa_auto_en state == TX REGISTER pd_aux, FIELD extpa_bias_en
CONTROL LOGIC
3 REGISTER extpa_msc, FIELD extpa_bias_mode
PABIAOP_ATB4 DAC
5 REGISTER extpa_cfg, FIELD extpa_bias REGISTER extpa_msc, FIELD extpa_bias_src
09322-019
Figure 40. Details of External PA Interface circuit
Rev. 0 | Page 32 of 72
ADF7241 RECEIVER
RECEIVE OPERATION
The two primary receiver operating modes are * * IEEE 802.15.4-2006 packet manager mode IEEE 802.15.4-2006 SPORT mode incoming frame, and all data following and including the frame length (PHR) is written to RX_BUFFER. If Register pkt_cfg, Field auto_fcs_off = 1, the FCS of the incoming frame is stored in RX_BUFFER. When the entire frame has been received, an rx_pkt_rcvd interrupt is asserted irrespective of the correctness of the FCS. If auto_fcs_off = 0, the radio controller calculates the FCS of the incoming frame according to the FCS polynomial defined in the IEEE 802.15.4-2006 standard (see Equation 1), and compares the result against the FCS of the incoming frame. An rx_pkt_rcvd interrupt is asserted only if both FCS fields match. The FCS is not written to RX_BUFFER but is replaced with the measured RSSI and signal quality indicator (SQI ) values of the received frame (see Figure 41).
The desired operating mode is selected with Register rc_cfg, Field rc_mode. The SPORT modes are explained in more detail in the SPORT Interface section. The output of the post demodulator filter is fed into a bank of correlators, which compare the incoming data sequences to the expected IEEE 802.15.4-2006 sequences. The receiver block operates in three primary states. * * * Preamble qualification Symbol timing recovery Data symbol reception
G16 (x) = x 16 + x 12 + x 5 + 1
(1)
During preamble qualification, the correlators check for the presence of preamble. When preamble is qualified, the device enters symbol timing recovery mode. The device symbol timing is achieved once a valid SFD is detected. The ADF7241 supports programmable SFDs. Refer to the Programmable SFD section for further details. The received symbols are then passed to the packet manager in packet mode or the SPORT interface in SPORT mode. In SPORT mode, four serial clocks are output on Pin TRCLK_CKO_GP3, and four data bits are shifted out on Pin DR_GP0 for each received symbol. Refer to the SPORT Interface section for further details. If in packet mode, when the packet manager determines the end of a packet, the ADF7241 automatically transitions to PHY_RDY or TX or remains in RX, depending on the setting in Register buffercfg, Field rx_buffer_mode (see Receiver Configuration in Packet Mode section). If in SPORT mode, the part remains in RX until the user issues a command to change to another state.
The behavior of the radio controller following the reception of a frame can be configured with Register buffercfg, Field rx_ buffer_mode (0x107[1:0]). With the default setting rx_buffer_ mode = 0, the part reverts automatically to PHY_RDY when an rx_pkt_rcvd interrupt condition occurs. This mode prevents RX_BUFFER from being overwritten by the next frame before the host MCU can read it from the ADF7241. This is because a new frame is always written to RX_BUFFER starting from the address stored in Register rxpb, Field rx_pkt_base (0x315[7:0]). Note that reception of the next frame is inhibited until the MAC delay following an RC_RX command has elapsed. If Register buffercfg, Field rx_buffer_mode = 1 (0x107[1:0]), the part remains in the RX state, and the reception of the next packet is enabled one MAC delay period after the frame has been written to RX_BUFFER. Depending on the network setup, this mode can cause an unnoticed violation of RX_BUFFER integrity if a frame arrives prior to the MCU having read the frame from RX_BUFFER. If Register buffercfg, Field rx_buffer_mode = 2 (0x107[1:0]), the reception of frames is disabled. This mode is useful for RSSI measurements and CCA, if the contents of RX_BUFFER are to be preserved.
Programmable SFD
An alternative to the standard IEEE 802.15.4-2006 SFD byte can optionally be selected by the user. The default setting of Register sfd_15_4, Field sfd_symbol_1 and Field sfd_symbol_2 (0x3F4[7:0]) is the standard IEEE 802.15.4-2006 SFD. If the user programs this register with an alternative value, this is used as the SFD in receive and transmit. The requirements are as follows: * * The value must not be a repeated symbol (for example, not 0x11 or 0x22). The value must not be similar to the preamble symbol (that is, not Symbol 0x0 or Symbol 0x8).
RECEIVER CALIBRATION
The receive path is calibrated each time an RC_RX command is issued. Figure 42 outlines the synthesizer and receive path calibration sequence and timing. The calibration step VCO_cal is omitted by setting Register vco_cal_cfg, Field skip_vco_cal = 15 (0x36F[3:0]), which is an option if the value of ch_freq[23:0] remains unchanged during transitions between the PHY_RDY, RX, and TX states. The synthesizer settling phase is always required because the PLL bandwidth is optimized differently for RX and TX operation. The static offset correction phase (OCL_stat) and dynamic offset correction phase (OCL_dyn) are also mandatory.
Receiver Configuration in Packet Mode
Packet management support is selected when Register rc_cfg, Field rc_mode = 0 (0x13E[7:0]). RX_BUFFER is overwritten when the ADF7241 enters the RX state following an RC_RX command and an SFD is detected. The SFD is stripped off the
Rev. 0 | Page 33 of 72
ADF7241
1 2 1 0 TO 20 ADDRESS INFORMATION n FRAME PAYLOAD 2
SEQ NUM
PHR
REGISTER pkt_cfg, FIELD auto_fcs_off = 1
REGISTER rxpb, FIELD rx_pkt_base 1 2 1 0 TO 20 ADDRESS INFORMATION n
REGISTER txpb, FIELD rx_pkt_base + 5 + (0 to 20) + n 1 1
SEQ NUM
REGISTER pkt_cfg, FIELD auto_fcs_off = 0
FRAME PAYLOAD
RSSI
PHR
FCF
FCS SQI
FCF
REGISTER rxpb, FIELD rx_pkt_base
REGISTER txpb, FIELD rx_pkt_base + 5 + (0 to 20) + n
Figure 41. IEEE 802.15.4-2006 Packet Fields Stored by the Packet Manager in RX_BUFFER
192s rx_mac_delay
0s TO 1020s mac_delay_ext
INIT 18s
VCO_cal 52s
SYNTH SETTLING 53s
OCL STATIC 10s
OCL DYNAMIC 55s
188s
Figure 42. RX Path Calibration
Rev. 0 | Page 34 of 72
09322-025
SKIPPED IF REGISTER vco_cal_cfg, FIELD skip_vco_cal = 15
09322-029
ADF7241
RECEIVE TIMING AND CONTROL
Register rc_cfg, Field rc_mode = 0 (0x13E[7:0]) for packet mode, and Register rc_cfg, Field rc_mode = 2 for RX SPORT mode. See the SPORT Interface section for details on the operation of the SPORT interface. By default, ADF7241 performs a synthesizer and a receiver path calibration immediately after it receives an RC_RX command. The transition into the RX state occurs after the receiver MAC delay has elapsed. The total receiver MAC delay is determined by the sum of the delay times configured in Register delaycfg0, Field rx_mac_delay (0x109[7:0]) and Register delaycfg2, Field mac_delay_ext (0x10B[7:0]). Register delaycfg0, Field rx_mac_delay (0x109[7:0]) is programmable in steps of 1 s, whereas Register delaycfg2, Field mac_delay_ext (0x10B[7:0]) is programmable in steps of 4 s. Register delaycfg2, Field mac_delay_ext is typically set to 0. It can, however, be dynamically used to accurately align the RX slot timing. Figure 43 shows the timing sequence for packet mode. If SPORT mode is enabled, the timing sequence is the same except that no rx_pkt_rcvd interrupt is generated and no automatic transition into the PHY_RDY state occurs. When entering the RX state, if Register cca2, Field rx_auto_cca = 1 (0x106[1]), a CCA measurement is started. The radio controller asserts a cca_complete interrupt when the CCA result is available in the status word. Upon detection of the SFD, the radio controller asserts an rx_sfd interrupt, which can be used by the host MCU for synchronization purposes. By default, the ADF7241 transitions into the PHY_RDY state when a valid frame has been received into RX_BUFFER and, if enabled, an rx_pkt_rcvd interrupt is asserted. This mechanism protects the integrity of RX_BUFFER. The RX state can be exited at any time by means of an appropriate radio controller command.
RECEIVED PACKET RC_RX RC_STATUS PREVIOUS STATE
PREAMBLE
SFD
PHR
PSDU
RX
PHY_RDY
rx_mac_delay + mac_delay_ext OPERATION RX CALIBRATION SFD SEARCH CCA OPTIONAL REGISTER irq_src1, FIELD cca_complete REGISTER irq_src0, FIELD rc_ready REGISTER irq_src1, FIELD rx_sfd REGISTER irq_src1, FIELD rx_pkt_rcvd
Figure 43. RX Timing and Control
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09322-022
ADF7241
CLEAR CHANNEL ASSESSMENT (CCA)
The CCA function of the ADF7241 complies with CCA Mode 1 as per IEEE 802.15.4-2006. A CCA can be specifically requested by means of an RC_CCA command or automatically obtained when the transceiver enters the RX state. In both cases, the start of the CCA averaging window is defined by when the RC_CCA or RC_RX command is issued and when the delay is configured in Register delaycfg0, Field rx_mac_delay (0x109[7:0]) and Register delaycfg2, Field mac_delay_ext (0x10B[7:0]). The CCA result is determined by comparing Register cca1, Field cca_thres (0x105[7:0]) against the average RSSI value measured throughout the CCA averaging window. If the measured RSSI value is less than the threshold value configured in Register cca1, Field cca_thres (0x105[7:0]), CCA_RESULT in the status word is set; otherwise, it is reset. The cca_complete interrupt is asserted when CCA_RESULT in the status word is valid. Figure 44 shows the timing sequence after issuing the RC_CCA command when Register cca2, Field continuous_cca = 0 (0x106[2]). Following the RC_CCA command, the transceiver starts the CCA observation window after the delay specified by the sum of Register delaycfg0, Field rx_mac_delay (0x109[7:0]) and Register delaycfg2, field mac_delay_ext (0x10b[7:0]) has elapsed. A cca_complete interrupt is asserted at the end of the CCA averaging window, and the transceiver enters the PHY_RDY state. When Register cca2, Field continuous_cca = 1 (0x106[2]), the transceiver remains in CCA state and continues to calculate CCA results repeatedly until a RC_PHY_RDY command is issued. This case is illustrated in Figure 45. The first cca_complete interrupt occurs when the first CCA averaging window after the RX MAC delay has elapsed. The transceiver then repeatedly restarts the CCA averaging window each time a cca_complete interrupt is asserted.
RC_CCA RC_STATUS PHY_RDY rx_mac_delay + mac_delay_ext RX CALIBRATION CCA CCA PHY_RDY
This configuration is useful for longer channel scans. CCA_ RESULT in the status word can be used to identify if the configured CCA RSSI threshold value has been exceeded during a CCA averaging period. Alternatively, the RSSI value in Register rrb, Field rssi_readback can be read by the host MCU after each cca_complete interrupt. As indicated in Figure 45, the RSSI readback value holds the results of the previous RSSI measurement cycle throughout the CCA averaging window and is updated only shortly before the cca_complete interrupt is asserted.
LINK QUALITY INDICATION (LQI)
The link quality indication (LQI) is defined in the IEEE 802.15.42006 standard as a measure of the signal strength and signal quality of a received IEEE 802.15.4-2006 frame. The ADF7241 makes several measurements available from which an IEEE 802.15.4-2006compliant LQI value can be calculated in the MCU. The first parameter is the RSSI value (see the Automatic Gain Control (AGC) and Receive Signal Strength Indicator (RSSI) subsection of the Receiver Radio Blocks section). The second parameter required for the LQI calculation can be read from Register lrb, Field sqi_readback (0x30D[7:0]), which contains an 8-bit value representing the quality of a received IEEE 802.15.4-2006 frame. It increases monotonically with the signal quality and must be scaled to comply with the IEEE 802.15.4-2006 standard. If the ADF7241 is operating in packet mode (Register rc_cfg, Field rc_mode = 0 (0x13E[7:0])), and Register pkt_cfg, Bit auto_fcs_off = 0 (0x108[0]), the SQI of a received frame is measured and stored together with the frame in RX_BUFFER. The SQI is measured over the entire packet and stored in place of the second byte of the FCS of the received frame in RX_BUFFER.
OPERATION
REGISTER irq_src0, FIELD rc_ready
Figure 44. CCA Timing Sequence, Register cca2, Field continuous_cca = 0 (0x106[2])
RC_CCA RC_STATUS PHY_RDY rx_mac_delay + mac_delay_ext
RX CALIBRATION
RC_PHY_RDY CCA PHY_RDY
OPERATION
CCA1 CCA2 X RSSI1 RSSI2
CCAn RSSIn
09322-028
REGISTER rrb, FIELD rssi_readback REGISTER irq_src1, FIELD cca_complete REGISTER irq_src0, FIELD rc_ready
Figure 45. CCA Timing Sequence, Register cca2, Field continuous_cca = 1 (0x106[2])
Rev. 0 | Page 36 of 72
09322-027
REGISTER irq_src1, FIELD cca_complete
ADF7241
AUTOMATIC TX-TO-RX TURNAROUND MODE
The ADF7241 features an automatic TX-to-RX turnaround mode when operating in IEEE 802.15.4-2006 packet mode. The automatic TX-to-RX turnaround mode facilitates the timely reception of acknowledgment frames. Figure 46 illustrates the timing of the automatic TX-to-RX turnaround mode. When enabled by setting Register buffercfg, Field auto_tx_to_rx_turnaround (0x107[3]), the ADF7241 automatically enters the RX state following the transmission of an IEEE 802.15.4-2006 frame. After the combined receiver MAC delay (Register delaycfg0, Field rx_mac_delay + Register delaycfg2, Field mac_delay_ext), the ADF7241 enters the RX state and is ready to receive a frame into RX_BUFFER. Subsequently, when a valid IEEE 802.15.4-2006 frame is received, the ADF7241 enters the PHY_RDY state.
Frame Filtering
Frame filtering is available when the ADF7241 operates in IEEE 802.15.4 packet mode. The frame filtering function rejects received frames not intended for the wireless node. The filtering procedure is a superset of the procedure described in Section 7.5.6.2 (third filtering level) of the IEEE 802.15.4-2006 standard. Field addon_en in Register pkt_cfg controls whether frame filtering is enabled
Automatic Acknowledgment
The ADF7241 has a feature that enables the automatic transmission of acknowledgment frames after successfully receiving a frame. The automatic acknowledgment feature of the receiver can only be used in conjunction with the IEEE 802.15.4 frame filtering feature. When enabled, an acknowledgment frame is automatically transmitted when the following conditions are met: * * * The received frame is accepted by the frame filtering procedure. The received frame is not a beacon or acknowledgment frame. The acknowledgment request bit is set in the FCF of the received frame.
IEEE 802.15.4 FRAME FILTERING, AUTOMATIC ACKNOWLEDGE, AND AUTOMATIC CSMA/CA
The following IEEE 802.15.4-2006 functions are enabled by the firmware module, RCCM_IEEEX: Automatic IEEE 802.15.4 frame filtering Automatic acknowledgment of received valid IEEE 802.15.4 frames * Automatic frame transmission using unslotted CSMA/CA with automatic retries See the Downloadable Firmware Modules and Writing to the ADF7241 sections for details on how to download a firmware module to the ADF7241. * *
PACKET TRANSMITTED
FRAME IN TX_BUFFER
PACKET RECEIVED
VALID IEEE802.15.4-2006 FRAME
RC_STATUS
TX
RX
PHY-RDY
rx_mac_delay + mac_delay_ext
REGISTER irq_src0, FIELD rc_ready REGISTER irq_src1, FIELD rx_pkt_rcvd
09322-030
REGISTER irq_src1, FIELD rx_pkt_sent
Figure 46. IEEE 802.15.4-2006 Auto TX-to-RX Turnaround Mode
Rev. 0 | Page 37 of 72
ADF7241
Figure 47 shows the format of the acknowledgment frame assembled by the ADF7241. The sequence number (Seq. Num.) is copied from the frame stored in RX_BUFFER. The automatic acknowledgment feature of the receiver uses TX_BUFFER to store the constructed acknowledgment frame prior to its transmission. Any data present in TX_BUFFER is overwritten by the acknowledgment frame prior to its transmission.
4 1 1 2 1 2
Automatic Unslotted CSMA/CA Transmit Operation
The automatic CSMA/CA transmit operation automatically performs all necessary steps to transmit frames in accordance with the IEEE 802.15.4-2006 standard for unslotted CSMA/CA network operation. It includes automatic CCA retries with random backoff, frame transmission, reception of the acknowledgment frame, and automatic retries in the case of transmission failure. Partial support is provided for slotted CSMA/CA operation. The number of CSMA/CA CCA retries can be specified between 0 and 5 in accordance with the IEEE 802.15.4 standard. The CSMA/CA can also be disabled, causing the transmission of the frame to commence immediately after the MAC delay has expired. This configuration facilitates the implementation of the transmit procedure in networks using slotted CSMA/CA. In this case, the timing of the CCA operation must be controlled by the host MCU, and the number of retries must be set to 1. Prior to the transmission of the frame stored in TX_BUFFER, the radio controller checks if the acknowledge request bit in the FCF of that frame is set. If it is set, then an acknowledgment frame is expected following the transmission. Otherwise, the transaction is complete after the frame has been transmitted. The acknowledgment request bit is Bit 5 of the byte located at the address contained in Register txpb, Field tx_packet_base + 1. Figure 48 depicts the automatic CSMA/CA operation. The firmware module download enables an additional command, RC_CSMACA, to initiate this CSMA/CA operation. It also enables an additional interrupt, csma_ca_complete, to be set to indicate when the CSMA/CA procedure is completed. As per the IEEE 802.15.4-2006 standard for unslotted CSMA/CA, the first CCA is delayed by a random number of backoff periods, where a unit backoff period is 320 s. The CCA is carried out for a period of 128 s as specified in the IEEE 802.15.4-2006 standard.
FRAME Tx RETRY LOOP SKIPPED IF ACK REQUEST BIT IS NOT SET ACK RX PHASE
SEQ. NUM.
PHR
SFD
Figure 47. ACK Frame Format
The transmission of the ACK frame starts after the combined delay given by the sum of the delays specified in Register delaycfg1, Field tx_mac_delay and Register delay_cfg2, Field mac_delay_ext has elapsed. The default settings of Register delaycfg1, Field tx_mac_delay = 192 and Register delay_cfg2, Field mac_delay_ext = 0 result in a delay of 192 s, which suits networks using unslotted CSMA/CA. Optionally, Register delay_cfg2, Field mac_delay_ext can be updated dynamically while the delay specified in Register delaycfg1, Field tx_mac_delay elapses. This option enables accurate alignment of the acknowledgment frame with the back-off slot boundaries in networks using slotted CSMA/CA. When the receiver automatic acknowledgment mode is enabled, the ADF7241 remains in the RX state until a valid frame has been received. When enabled, an rx_pkt_rcvd interrupt is generated. The ADF7241 then automatically enters the TX state until the transmission of the acknowledgment frame is complete. When enabled, a tx_pkt_sent interrupt is generated to signal the end of the transmission phase. Subsequently, the ADF7241 returns to the PHY_RDY state.
OPTION TO SKIP FOR SLOTTED CSMA/CA CSMA-CA PHASE RC_CSMACA COMMAND CCA
09322-065
PREAMBLE
FCS
FCF
FRAME TRANSMIT
RECEIVE ACK
rx_mac_delay 192s (def)
rnd(2BE - 1) 320s
128s
106s
192s
<864s
STATE
PREVIOUS STATE
CCA
TX
RX
PHY_RDY
09322-066
csma_ca_complete
Figure 48. Automatic CSMA/CA Transmit Operation (with CCA)
Rev. 0 | Page 38 of 72
ADF7241
If a busy channel is detected during the CCA phase, the radio controller performs the next delay/CCA cycle until the maximum number of CCA retries specified has been reached. If the maximum number of allowed CCA retries has been reached, the operation is aborted, and the device transitions to the PHY_RDY state. If the CCA is successful, the radio controller changes the device state from the CCA state to the TX state and transmits the frame stored in TX_BUFFER. The minimum turnaround time from RX to TX is 106 s. If neither the acknowledge request bit in the transmitted frame nor the csma_ca_turnaround bit are set, the device returns to the PHY_RDY state immediately upon completion of the frame transmission. Otherwise, it enters the RX state and waits for up to 864 s for an acknowledgment. If an acknowledgment is not received within this time and the maximum number of frame retries has not been reached, the ADF7241 remains inside the frame transmit retry loop and starts the next CSMA/CA cycle. Otherwise, it exits to the PHY_ RDY state. The procedure exits with a csma_ca_complete interrupt.
Automatic Gain Control (AGC) and Receive Signal Strength Indicator (RSSI)
The ADF7241 AGC circuit features fast overload recovery using dynamic bandwidth adjustments for fast preamble acquisition and optimum utilization of the dynamic range of the receiver path. The radio controller automatically enables the AGC after an offset correction phase, which is carried out when the transceiver enters the RX state. The RSSI readback value is continuously updated while the ADF7241 is in the RX state. The result is provided in Register rrb, Field rssi_readback (0x30C[7:0]) in decibels relative to 1 mW (dBm) using signed twos complement notation. The RSSI averaging window is synchronized with the start of the active RX phase at the end of the MAC delay following an RC_RX command. The RSSI averaging period is 128 s, or eight symbol periods, in compliance with the IEEE 802.15.4-2006 standard. If the ADF7241 is operating in the IEEE 802.15.4-2006 packet mode, the RSSI of received frames is measured and stored together with the frame in RX_BUFFER. The RSSI is measured in a window with a length of eight symbols immediately following the detected SFD. The result is then stored in place of the first byte of the FCS of the received frame in RX_BUFFER. It is also possible to compensate for systematic errors of the measured RSSI value and/or production tolerances by adjusting the RSSI readback value by an offset value that can be programmed in Register agc_cfg5, Field rssi_offs (0x3B9[4:2]). The adjustment resolution is in 1 dB steps.
RECEIVER RADIO BLOCKS
Baseband Filter
Baseband filtering on the ADF7241 is accomplished by a cascade of analog and digital filters. These are configured for optimum performance assuming a crystal frequency tolerance of 40 ppm.
Offset Correction Loop (OCL)
The ADF7241 is equipped with a fast and autonomous offset correction loop (OCL), which cancels both static and dynamic time-varying offset voltages present in the zero-IF receiver path. The OCL operates continuously and is not constrained by the formatting, timing, or synchronization of the data being received. The scheme is suitable for frequency hopping spreadspectrum (FHSS) communication systems.
Rev. 0 | Page 39 of 72
ADF7241 SPORT INTERFACE
The SPORT interface is a high speed synchronous serial interface suitable for interfacing to a wide variety of MCUs and DSPs, without the use of glue logic. These include, among others, the ADSP-21xx, SHARC, TigerSHARC and Blackfin DSPs. Figure 66 and Figure 67 show typical application diagrams using one of the available SPORT modes. The interface uses four signals, a clock output (TRCLK_CKO_GP3), a receive data output (DR_GP0), a transmit data input (DT_GP1), and a framing signal output (IRQ2_TRFS_GP2). The IRQ2 output functionality is not available while the SPORT interface is enabled. The SPORT interface supports receive and transmit operations. Table 19 lists the SPORT interface options. Refer to Device Configuration section for further details on register programming requirements. To use the SPORT interface for transmitting IEEE 802.15.4 the symbol chipping operation must be performed externally. SPORT interface remains active until an RC_RX command is reissued or the RX state is exited by another command. The rx_pkt_rvcd interrupt is not available in this mode. Figure 7 illustrates the timing for this configuration. Refer to Table 19 for details of pins relevant to the SPORT interface mode.
Receive Symbol Clock in SPORT Mode
The ADF7241 offers a symbol clock output option during IEEE 802.15.4 packet reception. This option is useful when a tight timing synchronization between incoming packets and the network is required, and the SFD interrupt (rx_sfd) cannot be used to achieve this. When in IEEE 802.15.4-2006 packet mode (Register rc_cfg, Field rc_mode = 0), set Register gp_cfg, Field gpio_config = 7 (0x32C[7:0]) to enable the symbol clock output.
SPORT Mode Transmit Operation
TX SPORT mode is enabled by setting Register rc_cfg, Field rc_mode = 3. It is necessary for the host MCU to perform the IEEE 802.15.4 chipping sequence in this mode. The data, sent through the SPORT interface on Pin DT_GP1, should be synchronized with the clock signal that appears on Pin TRCLK_ CKO_GP3. Figure 9 shows the timing for this configuration. The polarity of this clock signal can be set by Register gp_cfg, Field gpio_config. The tx_pkt_sent interrupt is not available in this mode. See Table 19 for details of pins relevant to this SPORT mode.
SPORT MODE
SPORT Mode Receive Operation
The ADF7241 provides an operating mode in which the SPORT interface is active and the packet manager is bypassed. It allows the reception of packets of arbitrary length. The mode is enabled by setting Register rc_cfg, Field rc_mode = 2 (0x13E[7:0]) and Register gp_cfg, Field gpio_config = 1 (0x32C[7:0]). When the SFD is detected, data and clock signals appear on the SPORT outputs, DR_GP0 and TRCLK_CKO_GP3, respectively. The
Table 19. SPORT Interface Configuration
Register gp_cfg, Field gpio_config 1 Register rc_cfg, Field rc_mode 2 IRQ2_TRFS_GP2 RX: ignore DR_GP0 RX: data output, changes at rising edge of data clock RX: Symbol 0 TX: ignore DT_GP1 RX: ignore RXEN_GP5 RX: ignore RXEN_GP6 RX: ignore TRCLK_CKO_GP3 RX: data clock
7 1
2 3
RX: ignore TX: ignore
4
3
TX: ignore
TX: ignore
RX: Symbol 1 TX: data input, sampled at rising edge of data clock TX: data input, sampled at falling edge of data clock
RX: Symbol 2 TX: ignore
RX: Symbol 3 TX: ignore
RX: symbol clock TX: data clock
TX: ignore
TX: ignore
TX: data clock
Rev. 0 | Page 40 of 72
ADF7241 DEVICE CONFIGURATION
After a cold start, or wake-up from sleep, it is necessary to configure the ADF7241. The device can be configured in two ways: an IEEE 802.15.4-2006 packet mode and an IEEE 802.15.4-2006 SPORT mode. Registers applicable to the setup each of the two primary modes are detailed in Table 22. Table 20 and Table 21 detail the values that should be written to the register locations given in Table 22 to configure the ADF7241 in the desired mode of operation. Table 20. Settings Required to Select Between LNA Port 1 and LNA Port 2
Address 0x39B[4] Register Field rxfe_cfg, lna_sel Value 0x0: LNA1 0x1: LNA2
Configuration Values for IEEE 802.15.4-2006 Packet and SPORT Modes
No register writes are required to configure IEEE 802.15.4 packet mode unless it is desired to select RF Port 1 rather than RF Port 2. For SPORT mode, the values detailed in Table 21 should be written to the ADF7241. Table 21. IEEE 802.15.4 Configuration Settings
Address 0x13E 0x306 0x32C Register Name rc_cfg tx_m gp_cfg Packet Mode N/A N/A N/A SPORT Mode See Table 19 0x01 See Table 19
CONFIGURATION VALUES
If it is desired to use RF Port 1 rather than RF Port 2 (see the RF Port Configurations/Antenna Diversity section), the value specific to the desired operating mode given in Table 20 should be written to the relevant register field.
Note that, if it is desired to use a nonstandard SFD, an additional register write is required. Refer to the Programmable SFD section for details.
Table 22. Register Writes Required to Configure the ADF7241
Register Group Description RFIO Port Packet/SPORT Mode Selection SPORT Mode Configuration Sync Word Transmit Filters
1
Register 0x39B 0x13E 0x32C 0x3F4 1 0x306
IEEE 802.15.4 Packet Mode Yes No No Yes1 No
IEEE 802.15.4 SPORT Mode Yes Yes Yes Yes1 Yes
This applies only when the user wishes to program a nonstandard SFD.
Rev. 0 | Page 41 of 72
ADF7241 RF PORT CONFIGURATIONS/ANTENNA DIVERSITY
ADF7241 is equipped with two fully differential RF ports. Port 1 is capable of receiving, whereas Port 2 is capable of receiving or transmitting. RF Port 1 comprises Pin RFIO1P and Pin RFIO1N, and RF Port 2 comprises Pin RFIO2P and Pin RFIO2N. Only one of the two RF ports can be active at any one time. The availability of two RF ports facilitates the use of switched antenna diversity and results in a simplified application circuit if the ADF7241 is connected to an external LNA and/or PA. Port selection for receive operation is configured through Register rxfe_cfg, Field lna_sel (0x39B[4]). preamble component of the packet. In a static communication system, it is often sufficient to select the optimum antenna once.
Configuration C
Configuration C shows that connecting an external PA and/or LNA is possible with a single external receive/transmit switch. The PA transmits on RF Port 2. RF Port 1 is configured as the receive input (Register rxfe_cfg, Field lna_sel = 0). ADF7241 provides two signals, RXEN_GP6 and TXEN_GP5, to automatically enable an external LNA and/or a PA. If Register ext_ctrl, Field txen_en = 1, the ADF7241 outputs a logic high level at the TXEN_GP5 pin while in TX state, and a logic low level while in any other state. If Register ext_ctrl, Field rxen_en = 1, the ADF7241 outputs a logic high level at the RXEN_GP6 pin while in RX state and a logic low level while in any other state. The RXEN_GP6 and TXEN_GP5 outputs have high impedance in the sleep state. Therefore, appropriate pull-down resistors must be provided to define the correct state of these signals during power-down. See the PA Ramping Controller section for further details on the use of an external PA, including details of the integrated biasing block, which simplifies connection to PA circuits based upon a single FET.
Configuration A
Configuration A of Figure 49 is the default connection where a single antenna is connected to RF Port 2. This selection is made by setting Register rxfe_cfg, Field lna_sel = 1 (default setting).
Configuration B
Configuration B shows a dual-antenna configuration that is suitable for switched antenna diversity. In this case, the link margin can be maximized by comparing the RSSI level of the signal received on each antenna and thus selecting the optimum antenna. In addition, the SQI value in Register lrb, Field sqi_readback can be used in the antenna selection decision. Suitable algorithms for the selection of the optimum antenna depend on the particulars of the underlying communication system. Switching between two antennas is likely to cause a short interruption of the received data stream. Therefore, it is advisable to synchronize the antenna selection phase with the
Configuration D
Configuration D is similar to Configuration A, except that a dipole antenna is used. In this case, a balun is not required.
RFIO1P 4 LNA RFIO1N 5 PA RFIO2P BALUN RFIO2N
6
RFIO1P BALUN RFIO1N
4
LNA
5
PA RFIO2P
6
LNA
7
BALUN
RFIO2N
LNA
7
A
B
RXEN_GP6 RFIO1P LNA BALUN RFIO1N
26 4
RFIO1P 4 LNA LNA RFIO1N 5 PA PA RFIO2P LNA MATCH NETWORK RFIO2N
6
5
RFIO2P PA BALUN RFIO2N
6 7 25
LNA
7
TXEN_GP5
09322-021
C
D
Figure 49. RF Interface Configuration Options (A: Single Antenna; B: Antenna Diversity; C: External LNA/PA; D: Dipole Antenna)
Rev. 0 | Page 42 of 72
ADF7241 AUXILLARY FUNCTIONS
TEMPERTURE SENSOR
To perform a temperature measurement, the MEAS state is invoked using the RC_MEAS command. The result can be read back from Register adc_rbk, Field adc_out (0x3AE[5:0]). Averaging multiple readings improves the accuracy of the result. The temperature sensor has an operating range from -40C to +85C. The die (ambient) temperature is calculated as follows: tdie = (4.72C x Register adc_rbk, Field adc_out) + 65.58C + correction value. where correction value can be determined by performing a readback at a single known temperature. Note also that averaging a number of ADC readbacks can improve the accuracy of the temperature measurement.
WAKE-UP CONTROLLER (WUC)
Circuit Description
The ADF7241 features a 16-bit wake-up timer with a programmable prescaler. The 32.768 kHz RC oscillator or the 32.768 kHz external crystal provides the clock source for the timer. This tick rate clocks a 3-bit programmable prescaler whose output clocks a preloadable 16-bit down counter. An overview of the timer circuit is shown in Figure 50 lists the possible division rates for the prescaler. This combination of programmable prescaler and 16-bit down counter gives a total WUC range of 30.52 s to 36.4 hours. Table 23. Prescaler Division Factors
timer_prescal (0x316[2:0]) 000 001 010 011 100 101 110 111 32.768 kHz Divider 1 4 8 16 128 1024 8,192 65,536 Tick Period 30.52 s 122.1 s 244.1 s 488.3 s 3.91 ms 31.25 ms 250 ms 2000 ms
BATTERY MONITOR
The battery monitor features very low power consumption and can be used in any state other than the sleep state. The battery monitor generates a batt_alert interrupt for the host MCU when the battery voltage drops below the programmed threshold voltage. The default threshold voltage is 1.7 V, and can be increased in 62 mV steps to 3.6 V with Register bm_cfg, Field battmon_voltage (0x3E6[4:0]).
An interrupt generated when the wake-up timer has timed out can be enabled in Register irq1_en0 or Register irq2_en0.
HARDWARE TIMER
tmr_cfg1[6:3] (ADDRESS 0x317) 32.768kHz RC OSCILLATOR
tmr_cfg0[2:0] (ADDRESS 0x316)
tmr_rld0[15:8], tmr_rld1[7:0] (ADDRESS 0x318, 0x319)
PRESCALER 32.768kHz XTAL 32.768kHz TICK RATE
16-BIT DOWN COUNTER
WAKE UP
irq_src0[2] (ADDRESS 0x3CB)
Figure 50. Hardware Wake-Up Timer Diagram
Rev. 0 | Page 43 of 72
09322-042
ADF7241
WUC Configuration and Operation
The wake-up timer can be configured as follows: * The clock signal for the timer is taken from the external 32.768 kHz crystal or the internal RC oscillator. This is selectable via Register tmr_cfg1, Field sleep_config (0x317[6:3]). A 3-bit prescaler, which is programmable via Register tmr_cfg0, Field timer_prescal (0x316[2:0]) determines the tick period. The calibration time is typically 1 ms. When the calibration is complete Register wuc_32khzosc_status, Field rc_osc_cal_ready is high. Following calibration, the host MCU can transition to the SLEEP_BBRAM_RCO sleep state, by following the full procedure given in the WUC Configuration and Operation section.
*
TRANSMIT TEST MODES
The ADF7241 has various transmit test modes that can be used in SPORT mode. These test modes can be enabled by writing to Register tx_test (Location 0x3F0), as described in Table 24. A continuous packet transmission mode is also available in packet mode. This mode can be enabled using the following procedure: 1. An IEEE 80.215.4-2006 packet with random payload should be written to TX_BUFFER as described in the Transmitter section. It is recommended to use a packet with the maximum length of 127 bytes. Set Register buffercfg, Field trx_mac_delay = 1. Set Register buffercfg, Field tx_buffer_mode = 3. Set Register pkt_cfg, Field skip_synth_settle = 1. Issue Command RC_TX. The transmitter continuously transmits the packet stored in TX_BUFFER. If Command RC_PHY_RDY is issued at any point after this step, all the preceding configuration registers must be rewritten to the device before reissuing Command RC_TX.
This is followed by a preloadable 16-bit down counter. After the clock is selected, the reload value for the down counter (tmr_rld0 and tmr_rld1) and the prescaler values (Register tmr_cfg0, Field timer_prescal) can be programmed. When the clock has been enabled, the counter starts to count down at the tick rate starting from the reload value. If wake-up interrupts are enabled, the timer unit generates an interrupt when the timer value reaches 0x0000. When armed, the wake-up interrupt triggers a wake-up from sleep. The reliable generation of wake-up interrupts requires the WUC timeout flag to be reset immediately after the reload value has been programmed. To do this, first write 1 and then write 0 to Register tmr_ctrl, Field wake_timer_flag_reset. To enable automatic wake-up from the sleep state, arm the timer unit for wake-up operation by writing 1 to Register tmr_cfg1, Field wake_on_timeout. After writing this sequence to the ADF7241, a sleep command can be issued.
2. 3. 4. 5. 6.
Calibrating the RC oscillator
The RC oscillator is not automatically calibrated. If it is desired to use the RC oscillator as the clock source for the WUC, the host MCU should initiate a calibration. This can be performed at any time in advance of entering the sleep state. To perform a calibration, the host MCU should * * Set Register tmr_ctrl, Field wuc_rc_osc_cal = 0 Set Register tmr_ctrl, Field wuc_rc_osc_cal = 1
Note that the transmitter momentarily transmits an RF carrier between packets due to a finite delay from when the packet handler finishes transmitting a packet in TX_BUFFER and going back to transmit the start of TX_BUFFER again.
Table 24. 0x3F0: tx_test
Bit [7:2] 1 0 Name Reserved carrier_only Reserved R/W R/W R/W R/W Reset Value 2 0 0 Description Reserved, set to default. Transmits unmodulated tone at the programmed frequency fCH. Reserved, set to default.
Rev. 0 | Page 44 of 72
ADF7241 SERIAL PERIPHERAL INTERFACE (SPI)
GENERAL CHARACTERISTICS
The ADF7241 is equipped with a 4-wire SPI interface, using the SCLK, MISO, MOSI, and CS pins. The ADF7241 always acts as a slave to the host MCU. Figure 51 shows an example connection diagram between the host MCU and the ADF7241. The diagram also shows the direction of the signal flow for each pin. The SPI interface is active and the MISO output enabled only while the CS input is low. The interface uses a word length of eight bits, which is compatible with the SPI hardware of most microprocessors. The data transfer through the SPI interface occurs with the most significant bit of address and data first. Refer to Figure 3 for the SPI interface timing diagram. The MOSI input is sampled at the rising edge of SCLK. As commands or data are shifted in from the MOSI input at the SCLK rising edge, the status word or data is shifted out at the MISO pin synchronous with the SCLK clock falling edge. If CS is brought low, the most significant bit of the status word appears on the MISO output without the need for a rising clock edge on the SCLK input.
VBAT
All commands are executed after CS goes high again or at the next positive edge of the SCLK input. The latter condition occurs in the case of a memory access command. In this case, the command is executed on the positive SCLK clock edge corresponding to the most significant bit of the first parameter word. The CS input must be brought high again after a command has been shifted into the ADF7241 to enable the recognition of successive command words. This is because a single command can be issued only during a CS low period (with the exception of a double NOP command).
CS
MOSI
RC OR SPI COMMAND
09322-038
MISO
STATUS
Figure 52. Command Write
ADF7241
CS SCLK MOSI MISO
PF1 SCLK MOSI MISO GPI RFS DR DT TSCLK
09322-031
IRQ1_GP4 IRQ2_TRFS_GP2 DR_GP0 DT_GP1 TRCLK_CKO_GP3
ADSP-21xx OR BLACKFIN DSP
RSCLK
Figure 51. SPI Interface Connection
COMMAND ACCESS
The ADF7241 is controlled through commands. Command words are single-byte instructions that control the state transitions of the radio controller and access to the registers and packet RAM. The complete list of valid commands is given in Table 25. Commands with the RC prefix are handled by the radio controller, whereas memory access commands, which have the SPI prefix are handled by an independent controller. Thus, SPI commands can be issued independent of the state of the radio controller. A command is initiated by bringing CS low and shifting in the command word over the SPI as shown in Figure 52.
The execution of certain commands by the radio controller may take several instruction cycles, during which the radio controller unit is busy. Prior to issuing a radio controller command, it is, therefore, necessary to read the status word to determine if the ADF7241 is ready to accept a new radio controller command. This is best accomplished by shifting in SPI_NOP commands, which cause status words to be shifted out. The RC_READY variable is used to indicate when the radio controller is ready to accept a new RC command, whereas the SPI_READY variable indicates when the memory can be accessed. To take the burden of repeatedly polling the status word off the host MCU for complex commands such as RC_RX, RX_TX, and RC_PHY_RDY, the IRQ handler can be configured to generate an RC_READY interrupt. See the Interrupt Controller section for details. Otherwise, the user can program timeout periods according to the command execution times provided under the state transition timing given in Table 10.
STATUS WORD
The status word of the ADF7241 is automatically returned over the MISO each time a byte is transferred over the MOSI. The meaning of the various status word bit fields is illustrated in Table 26. The RC_STATUS field reflects the current state of the radio controller. By definition, RC_STATUS reflects the state of a completed state transition. During the state transition, RC_STATUS maintains the value of the state from which the state transition was invoked.
Rev. 0 | Page 45 of 72
ADF7241
Table 25. Command List
Command SPI_NOP SPI_PKT_WR SPI_PKT_RD SPI_MEM_WR SPI_MEM_RD SPI_MEMR_WR SPI_MEMR_RD SPI_PRAM_WR RC_SLEEP RC_IDLE RC_PHY_RDY RC_RX RC_TX RC_MEAS RC_CCA RC_PC_RESET RC_RESET Code 0xFF 0x10 0x30 0x18 + memory address[10:8] 0x38 + memory address[10:8] 0x08 + memory address[10:8] 0x28 + memory address[10:8] 0x1E 0xB1 0xB2 0xB3 0xB4 0xB5 0xB6 0xB7 0xC7 0xC8 Description No operation. Use for dummy writes. Write data to the packet RAM starting from the transmit packet base address pointer, Register txpb, Field tx_pkt_base (0x314[7:0]). Read data from the packet RAM starting from the receive packet base address pointer, Register rxpb, Field rx_pkt_base (0x315[7:0]). Write data to MCR or packet RAM sequentially. Read data from MCR or packet RAM sequentially. Write data to MCR or packet RAM as a random block. Read data from MCR or packet RAM as a random block. Write data to the program RAM. Invoke transition of the radio controller into the sleep state Invoke transition of the radio controller into the idle state Invoke transition of the radio controller into the PHY_RDY state Invoke transition of the radio controller into the RX state Invoke transition of the radio controller into the TX state Invoke transition of the radio controller into the MEAS state Invoke clear channel assessment Program counter reset. This should only be used after a firmware download to the program RAM Resets the ADF7241 and puts it in the sleep state
Table 26. SPI Status Word
Bit 7 6 Name SPI_READY IRQ_STATUS Description 0: SPI is not ready for access. 1: SPI is ready for access. 0: no pending interrupt condition. 1: pending interrupt condition. (IRQ_STATUS = 1 when either the IRQ1_GP4 or IRQ2_TRFS_GP2 pin is high) 0: radio controller is not ready to accept RC_xx command strobe. 1: radio controller is ready to accept new RC_xx command strobe. 0: channel busy. 1: channel idle. Valid when Register irq_src1, Bit cca_complete (0x3CC[0]) is asserted. Radio controller status: 0: reserved. 1: idle. 2: MEAS. 3: PHY_RDY. 4: RX. 5: TX. 6 to 15: reserved.
5 4
RC_READY CCA_RESULT
[3:0]
RC_STATUS
Rev. 0 | Page 46 of 72
ADF7241 MEMORY MAP
The various memory locations used by the ADF7241 are shown in Figure 53. The radio control and packet management of the part are realized through the use of an 8-bit, custom processor, and an embedded ROM. The processor executes instructions stored in the embedded program ROM. There is also a local RAM, subdivided into three sections, that is used as a data packet buffer, both for transmitted and received data (packet RAM), and for storing the radio and packet management configuration (BBRAM and MCR). The RAM addresses of these variables are 11 bits in length.
PROGRAM RAM
The program RAM consists of 2 kB of volatile memory. This memory space is used for various software modules, such as address filtering and CSMA/CA, which are available from Analog Devices. The software modules are downloaded to the program RAM memory space over the SPI by the host microprocessor. See the Program RAM Write subsection of the Memory Access section for details on how to write to the program RAM.
BBRAM
The 64-byte battery back-up, or BBRAM, is used to maintain settings needed at wake-up from sleep state by the wake-up controller.
PACKET RAM
The packet RAM consists of 256 bytes of memory space from Address 0x000 to Address 0x0FF, as shown in Figure 53. This memory is allocated for storage of data from valid received packets and packet data to be transmitted. The packet manager stores received payload data at the memory location indicated by the value of Register rxpb, Field rx_pkt_base, the receive address pointer. The value of Register txpb, Field tx_pkt_base, the transmit address pointer, determines the start address of data to be transmitted by the packet manager. This memory can be arbitrarily assigned to store single or multiple transmit or receive packets, both with and without overlap as shown in Figure 54. The rx_pkt_base value should be chosen to ensure that there is enough allocated packet RAM space for the maximum receiver payload length.
11-BIT ADDRESSES
MODEM CONFIGURATION RAM (MCR)
The 256-byte modem configuration RAM, or MCR, contains the various registers used for direct control or observation of the physical layer radio blocks of the ADF7241. Contents of the MCR are not retained in the sleep state.
PROGRAM ROM
The program ROM consists of 4 kB of nonvolatile memory. It contains the firmware code for radio control, packet management, and smart wake mode.
0x3FF
REGISTER prampg, FIELD pram_page[3:0] ADDRESS [7:0] CS MISO MOSI SCLK SPI
PROGRAM RAM 2kB
MCR 256 BYTES
0x300
NOT USED PROGRAM ROM 4kB
0x13F
BBRAM 64 BYTES SPI/PH MEMORY ARBITRATION INSTRUCTION/DATA [7:0] ADDRESS/ DATA MUX
0x100 0x0FF
PACKET MANAGER CLOCK
PACKET MANAGER
PACKET RAM 256 BYTES
0x000
09322-070
8-BIT PROCESSOR
ADDRESS[10:0] DATA[7:0]
Figure 53. ADF7241 Memory Map
Rev. 0 | Page 47 of 72
ADF7241
TRANSMIT AND RECEIVE PACKET tx_pkt_base TRANSMIT PAYLOAD 0x000 tx_pkt_base rx_pkt_base 256-BYTE TRANSMIT OR RECEIVE PACKET 0x000 tx_pkt_base (PACKET 1) tx_pkt_base (PACKET 2) TRANSMIT PAYLOAD 2 rx_pkt_base (PACKET 1) RECEIVE PAYLOAD rx_pkt_base (PACKET 2) RECEIVE PAYLOAD 2 0x0FF 0x0FF 0x0FF
09322-071
MULTIPLE TRANSMIT AND RECEIVE PACKETS 0x000 TRANSMIT PAYLOAD
rx_pkt_base RECEIVE PAYLOAD
TRANSMIT OR RECEIVE PAYLOAD
Figure 54. Example Packet RAM Configurations Using the Transmit Packet and Receive Packet Address Pointers
Rev. 0 | Page 48 of 72
ADF7241 MEMORY ACCESS
Memory locations are accessed by invoking the relevant SPI command. An 11-bit address is used to identify registers or locations in the memory space. The most significant three bits of the address are incorporated into the command by appending them as the LSBs of the command word. Figure 55 illustrates the command, address, and data partitioning. The various SPI memory access commands are different depending on the memory location being accessed. This is described in Table 27. An SPI command should be issued only if the SPI_READY bit of the status word is high. In addition, an SPI command should not be issued while the radio controller is initializing. SPI commands can be issued in any radio controller state including during state transition.
CS
SPI_MEM_WR
MEMORY ADDRESS BITS[7:0]
DATA BYTE
MOSI 5 BITS MEMORY ADDRESS BITS[10:0] DATA n x 8 BITS
09322-072
Figure 55. SPI Memory Access Command/Address Format
Table 27. Summary of SPI Memory Access Commands
SPI Command SPI_PKT_WR SPI_PKT_RD SPI_MEM_WR Command Value = 0x10 = 0x30 = 0x18 (packet RAM) = 0x19 (BBRAM) = 0x1B (MCR) = 0x38 (packet RAM) = 0x39 (BBRAM) = 0x3B (MCR) = 0x08 (packet RAM) = 0x09 (BBRAM) = 0x0B (MCR) = 0x28 (packet RAM) = 0x29 (BBRAM) = 0x2B (MCR) =0x1E (program RAM) = 0x3E (program RAM) = 0xFF Description Write telegram to the packet RAM starting from the transmit packet base address pointer, Register txpb, Field tx_pkt_base (0x314[7:0]). Read telegram from the packet RAM starting from receive packet base address pointer, Register rxpb, Field rx_pkt_base (0x315[7:0]). Write data to BBRAM, MCR, or packet RAM sequentially. An 11-bit address is used to identify memory locations. The most significant three bits of the address are incorporated into the command (xxxb). This command is followed by the remaining eight bits of the address. Read data from BBRAM, MCR, or packet RAM sequentially. An 11-bit address is used to identify memory locations. The most significant three bits of the address are incorporated into the command (xxxb). This command is followed by the remaining eight bits of the address, which is subsequently followed by the appropriate number of SPI_NOP commands. Write data to BBRAM/MCR or packet RAM at random.
SPI_MEM_RD
SPI_MEMR_WR
SPI_MEMR_RD
Read data from BBRAM/MCR or packet RAM at random.
SPI_PRAM_WR SPI_PRAM_RD SPI_NOP
Write data to program RAM. Read data from program RAM No operation. Use for dummy writes when polling the status word and used as dummy data on the MOSI line when performing a memory read.
Rev. 0 | Page 49 of 72
ADF7241
WRITING TO THE ADF7241
Block Write
Packet RAM memory locations can be written to in block format using the SPI_PKT_WR. The SPI_PKT_WR command is 0x10. This command provides pointer-based write access to the packet RAM. The address of the location written to is calculated from the base address in Register txpb, Field tx_pkt_base (0x314[7:0]), plus an index. The index is zero for the first data word following the command word and is auto-incremented for each consecutive data word written. The first data word following an SPI_PKT_WR command is, thus, stored in the location with Address txpb, Field tx_pkt_base (0x314[7:0]), the second in packet RAM location with Address txpb, Field tx_pkt_base + 1, and so on. This feature makes this command efficient for bulk writes of data that recurrently begin at the same address. Figure 56 shows the access sequence for Command SPI_PKT_WR. The MCR, BBRAM, and packet RAM memory locations can be written to in block format using the SPI_MEM_WR command. The SPI_MEM_WR command code is 00011xxxb, where xxxb represent Bits[10:8] of the first 11-bit address. If more than one data byte is written, the write address is automatically incremented for every byte sent until CS is set high, which terminates the memory access command. See Figure 57 for more details. The maximum block write for the MCR, packet RAM, and BBRAM memories are 256 bytes, 256 bytes, and 64 bytes, respectively. These maximum block-write lengths should not be exceeded. relative location of a byte to Address Pointer rx_pkt_base (Register rxpb; 0x315[7:0]) or Address Pointer tx_pkt_base (Register txpb; 0x314[7:0]), respectively.
Program RAM Write
The program RAM can only be written to using the memory block write, as illustrated in Figure 59. The SPI_PRAM_WR command is 0x1E. The program RAM is organized in eight pages with a length of 256 bytes each. The code module must be stored in the program RAM starting from Address 0x0000, or Address 0x00 in Page 0. The current program RAM page is selected with Register prampg, Field pram_page (0x313[3:0]). Prior to uploading the program RAM, the radio controller code module must be divided into blocks of 256 bytes commensurate with the size of the program RAM pages. Each 256-byte block is uploaded into the currently selected program RAM page using the SPI_PRAM_WR command. Figure 59 illustrates the sequence required for uploading a code block of 256 bytes to a PRAM page. The SPI_PRAM_WR command code is followed by Address Byte 0x00 to align the code block with the base address of the program RAM page. Figure 60 shows the overall upload sequence. With the exception of the last page written to the program RAM, all pages must be filled with 256 bytes of module code.
READING FROM THE ADF7241
Block Read
Command SPI_PKT_RD provides pointer-based read access from the packet RAM. The SPI_PKT_RD command is 0x30. The address of the location to be read is calculated from the base address in Register rxpb, Field rx_pkt_base, plus an index. The index is zero for the first readback word. It is auto-incremented for each consecutive SPI_NOP command. The first data byte following a SPI_PKT_RD command is invalid and should be ignored. Figure 61 shows the access sequence for Command SPI_PKT_RD. The SPI_MEM_RD command can be used to perform a block read of MCR, BBRAM, and packet RAM memory locations. The SPI_MEM_RD command code is 00111xxxb, where xxxb represent Bits[10:8] of the first 11-bit address. This command is followed by the remaining eight bits of the address to be read and then two SPI_NOP commands (dummy byte). The first byte available after writing the address should be ignored, with the second byte constituting valid data. If more than one data byte is to be read, the read address is automatically incremented for subsequent SPI_NOP commands sent. See Figure 62 for more details.
Example
Write 0x00 to the rc_cfg register (Location 0x13E). * * * * * The first five bits of the SPI_MEM_WR command are 00011. The 11-bit address of rc_cfg is 00100111110. The first byte sent is 00011001 or 0x19. The second byte sent is 00111110 or 0x3E. The third byte sent is 0x00.
Thus, 0x193F00 is written to the part.
Random Address Write
MCR, BBRAM, and packet RAM memory locations can be written to in random address format using the SPI_MEMR_WR command. The SPI_MEMR_WR command code is 00001xxxb, where xxxb represent Bits[10:8] of the 11-bit address. The lower eight bits of the address should follow this command and then the data byte to be written to the address. The lower eight bits of the next address are entered followed by the data for that address until all required addresses within that block are written, as shown in Figure 58. Note that the SPI_MEMR_WR command facilitates the modification of individual elements of a packet in RX_BUFFER and TX_BUFFER without the need to download and upload an entire packet. The address location of a particular byte in RX_BUFFER and TX_BUFFER in the packet RAM is determined by adding the
Random Address Read
MCR, BBRAM, and Packet RAM memory locations can be read from in a nonsequential manner using the SPI_MEMR_RD command. The SPI_MEMR_RD command code is 00101xxxb, where xxxb represent Bits[10:8] of the 11-bit address. This command is followed by the remaining eight bits of the address to be written and then two SPI_NOP commands (dummy byte).
Rev. 0 | Page 50 of 72
ADF7241
The data byte from memory is available on the second SPI_NOP command. For each subsequent read, an 8-bit address should be followed by two SPI_NOP commands as shown in Figure 63. Thus, 0x393EFFFF is written to the part. The value shifted out on the MISO line while the fourth byte is sent is the value stored in the rc_cfg register. This allows individual elements of a packet in RX_BUFFER and TX_BUFFER to be read without the need to download the entire packet.
Example
Read the value stored in the rc_cfg register. * * * * * * The first five bits of the SPI_MEM_RD command are 00111. The 11-bit address of rc_cfg register is 00100111111. The first byte sent is 00111001, or 0x39. The second byte sent is 00111110, or 0x3E. The third byte sent is 0xFF (SPI_NOP). The fourth byte sent is 0xFF.
Program RAM Read
The SPI_PRAM_RD command is used to read from the program RAM. This may be performed to verify that a firmware module has been correctly written to the program RAM. Like the SPI_PRAM_WR command, the host MCU must select the program RAM page to read via Register prampg, Field pram_page. Following this, the host MCU may use the SPI_PRAM_RD command to block read the selected program RAM page. The structure of this command is identical to the SPI_MEM_RD command.
[MAX N = (256 - tx_pkt_base)]
CS
MOSI
SPI_PKT_WR
DATA FOR ADDRESS
DATA FOR ADDRESS
DATA FOR ADDRESS
DATA FOR ADDRESS
DATA FOR ADDRESS
[tx_pkt_base]
[tx_pkt_base + 1]
[tx_pkt_base + 2]
[tx_pkt_base + 3]
[tx_pkt_base + N]
09322-033
09322-036 09322-032
MISO
STATUS
STATUS
STATUS
STATUS
STATUS
STATUS
Figure 56. Packet RAM Write (tx_pkt_base is the address base pointer value for TX, which is programmed in Register txbp, Bit tx_pkt_base.)
CS
[MAX N = (256 - INITIAL ADDRESS)]
MOSI
SPI_MEM_WR
ADDRESS
DATA FOR [ADDRESS]
DATA FOR [ADDRESS + 1]
DATA FOR [ADDRESS + 2]
DATA FOR [ADDRESS + N]
MISO
STATUS
STATUS
STATUS
STATUS
STATUS
STATUS
Figure 57. Memory (Register or Packet RAM) Block Write
CS
MOSI
SPI_MEMR_WR
ADDRESS 1
DATA 1
ADDRESS 2
DATA 2
DATA N
MISO
STATUS
STATUS
STATUS
STATUS
STATUS
STATUS
Figure 58. Memory (Register or Packet RAM) Random Address Write
Rev. 0 | Page 51 of 72
ADF7241
CS
MOSI
SPI_MEM_WR +0x03
0x13
PAGE NUMBER n
SPI_PRAM_WR
0x00
CODE[0x00]
CODE[0xFF]
MISO
STATUS
STATUS
STATUS
STATUS
STATUS
STATUS
STATUS
SET PRAM PAGE NUMBER n
UPLOAD 256 BYTES OF CODE TO PRAM PAGE NUMBER n
Figure 59. Upload Sequence for a Program RAM Page
SET PRAM PAGE 0
DOWNLOAD 256 BYTES BLOCK 0 DOWNLOAD 256 BYTES BLOCK 0 SET PRAM PAGE 1 SET PRAM PAGE 2 TO PRAM PAGE 0 TO PRAM PAGE 1
Figure 60. Download Sequence for Code Module
CS
MAX N = (256 - tx_pkt_base)
MOSI
SPI_PKT_RD
SPI_NOP
SPI_NOP
SPI_NOP
SPI_NOP
SPI_NOP
09322-074
09322-073
MISO
STATUS
STATUS
DATA FROM ADDRESS
DATA FROM ADDRESS
DATA FROM ADDRESS
DATA FROM ADDRESS
rx_pkt_base
rx_pkt_base + 1
rx_pkt_base + 2
rx_pkt_base + N
Figure 61. Packet RAM Read (rx_pkt_base is the address base pointer value for RX, which is programmed in Register rxbp, Bit rx_pkt_base.)
CS
[MAX N = (256 - INITIALADDRESS)]
MOSI
SPI_MEM_RD
ADDRESS
SPI_NOP
SPI_NOP
SPI_NOP
SPI_NOP
MISO
STATUS
STATUS
STATUS
DATA FROM ADDRESS
DATA FROM ADDRESS + 1
DATA FROM ADDRESS + N
Figure 62. Memory (Register or Packet RAM) Block Read
CS
MOSI
SPI_MEM_RD
ADDRESS 1
ADDRESS 2
ADDRESS 3
ADDRESS 4 DATA FROM ADDRESS 2
ADDRESS N
SPI_NOP
SPI_NOP
Figure 63. Memory (Register or Packet RAM) Random Address Read
Rev. 0 | Page 52 of 72
09322-037
MISO
STATUS
STATUS
STATUS
DATA FROM ADDRESS 1
DATA FROM
ADDRESS N - 2
DATA FROM
ADDRESS N - 1
DATA FROM ADDRESS N
09322-034
09322-035
ADF7241 DOWNLOADABLE FIRMWARE MODULES
The program RAM of the ADF7241 can be used to store firmware modules for the on-chip processor that provide extra functionality. The executable code for these firmware modules and details on their functionality are available from Analog Devices. See the Writing to the ADF7241 section for details on how to download these firmware modules to program RAM.
Rev. 0 | Page 53 of 72
ADF7241 INTERRUPT CONTROLLER
CONFIGURATION
The ADF7241 is equipped with an interrupt controller that is capable of handling up to 16 independent interrupt events. The interrupt events can be triggered either by hardware circuits or the packet manager and are captured in Register irq_src0 (0x3CB) and Register irq_src1(0x3CC). The interrupt signals are available on two interrupt pins: IRQ1_ GP4 and IRQ2_TRFS_GP2. Each of the 16 interrupt sources can be individually enabled or disabled. The irq1_en0 (0x3C7) and irq1_en1 (0x3C8) registers control the functionality of the IRQ1_GP4 interrupt pin. The irq2_en0 (0x3C9) and irq2_en1 (0x3CA) registers control the functionality of the IRQ2_TRFS_ GP2 interrupt pin. Refer to Table 28 and Table 29 for details on which bits in the relevant interrupt source and interrupt enable registers correspond to the different interrupts. The IRQ_STATUS bit of the SPI status word, is asserted if an interrupt is present on either IRQ1 or IRQ2. This is useful for host MCUs that may not have interrupt pins available. The irq_src1 and irq_src0 registers can be read back to establish the source of an interrupt. An interrupt is cleared by writing 1 to the corresponding bit location in the appropriate interrupt source register (irq_src1 or irq_src0). If 0 is written to a bit location in the interrupt source registers, its state remains unchanged. This scheme allows interrupts to be cleared individually and facilitates hierarchical interrupt processing. The availability of two interrupt outputs permits a flexible allocation of interrupt source to two different MCU hardware
REGISTER irq_src1
cca_complete rx_pkt_rcvd tx_pkt_sent RESERVED RESERVED RESERVED RESERVED
resources. For instance, an rx_sfd interrupt can be associated with a timer-capture unit of the MCU, while all other interrupts are handled by a normal interrupt handling routine. When operating in SPORT mode, Pin IRQ2_TRFS_GP2 acts as a frame synchronization signal and is disconnected from the interrupt controller. When in the sleep state, the IRQ1_GP4 and IRQ2_TRFS_GP2 pins have high impedance. When not in the sleep state, Pin IRQ1_GP4 and Pin IRQ2_ TRFS_GP2 are configured as push-pull outputs, using positive logic polarity. Following a power-on reset or wake-up from sleep, Register irq1_en0, Field powerup and Register irq2_en0, Field powerup are set, while all other bits in the irq1_en0, irq1_en1, irq2_en0, and irq2_en1 registers are reset. Therefore, a power-up interrupt signal is asserted on the IRQ1_GP4 and IRQ2_TRFS_GP2 pins after a power-on-reset event or wake-up from the sleep state. Provided the wake-up from sleep event is caused by the wakeup timer, the power-up interrupt signal can be used to power up the host MCU. After the ADF7241 is powered up, the rc_ready, wake-up, and power-on reset interrupts are also asserted in the irq_src0 register. However, these interrupts are not propagated to the IRQ1_GP4 and IRQ2_TRFS_GP2 pins because the corresponding mask bits are reset. The irq_src0 and irq_src1 registers should be cleared during the initialization phase.
REGISTER irq_src0
RESERVED RESERVED
batt_alert
15 14 13 12 11 10 9 INTERRUPT MASKS (2 x 16 INDEPENDENT INTERRUPT MASKS)
8
7
6
5
4
3
2
powerup
rc_ready
INTERRUPT SOURCES (16 INTERRUPT SOURCES AVAILABLE)
wakeup
rx_sfd
tx_sfd
por
1
0
REGISTER irq1_en1
REGISTER irq1_en0
REGISTER irq2_en1
REGISTER irq2_en0
INTERRUPT OUTPUTS (2 INTERRUPT PINS AND INTERRUPT PENDING BIT AVAILABLE ON THE STATUS_WORD)
09322-094
IRQ1_GP4
Status_word[6]
IRQ2_TRFS_GP2
Figure 64. Interrupt Controller
Rev. 0 | Page 54 of 72
ADF7241
Table 28. Bit Locations in the Interrupt Source Register irq_src1, with Corresponding Interrupt Enables in irq1_en1, irq2_en1
Bit 7 6 5 4 3 2 1 0 Name Reserved Reserved Reserved tx_pkt_sent rx_pkt_rcvd tx_sfd rx_sfd cca_complete Notes Don't care; set mask to 0. Don't care; set mask to 0. Don't care; set mask to 0. TX packet transmission complete. Packet received in RX_BUFFER. SFD has been transmitted. SFD has been detected. CCA_RESULT in status word is valid.
tx_sfd
This interrupt is asserted if the SFD is transmitted when in IEEE 802.15.4-2006 packet mode.
rx_sfd
This interrupt is asserted if a SFD is detected while in the RX state in either IEEE 802.15.4 mode.
cca_complete
The interrupt is asserted at the end of a CCA measurement following a RC_RX or RC_CCA command. The interrupt indicates that the CCA_RESULT flag in the status word is valid.
batt_alert
The interrupt is asserted if the battery monitor signals a battery alarm. This occurs when the battery voltage drops below the programmed threshold value. The battery monitor must be enabled and configured. See the Battery Monitor section for further details.
Table 29. Bit Locations in the Interrupt Source Register irq_src0, with Corresponding Interrupt Enables in irq1_en0, irq2_en0
Bit 7 6 5 4 3 2 1 0 Name Reserved Reserved batt_alert por rc_ready wakeup powerup Reserved Notes Don't care; set mask to 0. Don't care; set mask to 0. Battery voltage has dropped below programmed threshold value. Power-on reset event. Radio controller ready to accept new command. Timer has timed out. Chip is ready for access. Don't care; set mask to 0.
rc_ready
The interrupt is asserted if the radio controller is ready to accept a new command. This condition is equivalent to the rising edge of the RC_READY flag in the status word.
wakeup
The interrupt is asserted if the WUC timer has decremented to zero. Prior to enabling this interrupt, the WUC timer unit must be configured with the tmr_cfg0, tmr_cfg1, tmr_rld0, and tmr_rld1 registers. A wake-up interrupt can be asserted while the ADF7241 is active or has woken up from the sleep state through a timeout event. See the Wake-Up Controller (WUC) section or further details.
DESCRIPTION OF INTERRUPT SOURCES
tx_pkt_sent
This interrupt is asserted when in IEEE 802.15.4-2006 packet mode and the transmission of a packet in TX_BUFFER is complete. rx_pkt_rcvd This interrupt is asserted when in IEEE 802.15.4-2006 packet mode and a packet with a valid FCS has been received and is available in RX_BUFFER.
powerup
The interrupt is asserted if the ADF7241 is ready for SPI access following a wake-up from the sleep state. This condition reflects a rising edge of the flag SPI_READY in the status word. If the ADF7241 has been woken up from the sleep state using the CS input, this interrupt is useful to detect that the ADF7241 has powered up without the need to poll the MISO output. Register irq1_mask, Field powerup and Register irq2_mask, Field powerup are automatically set on exit from the sleep state. Therefore, this interrupt is generated when a transition from sleep is triggered by CS being pulled low or by a timeout event.
Rev. 0 | Page 55 of 72
ADF7241 APPLICATIONS CIRCUITS
C15 C14 C39 C40 C41 C28
32kHz
SENSOR SCS MOSI
VBAT
SCLK MISO 32 31
PABIAOP_ATB4 PAVSUP_ATB3
30
VDD_BAT
29 28 27 26
XOSC32KN_ATB2 XOSC32KP_GP7_ATB1 CREGDIG1 RXEN_GP6
25
TXEN_GP5
R10
C18 C21 GND UNBAL GND BALM 10 BALP C22
R12
C17
C16 1 2 3 4 5 6 CREGRF1 RBIAS CREGRF2 RFIO1P RFIO1N RFIO2P RFIO2N CREGRF3
MICROCONTROLLER GPIO0
24 CS MOSI SCLK MISO 23 22 21 20 19 18 17
GPIO1 MOSI SCLK MISO IRQ1IN IRQ2IN
ADF7241
IRQ1_GP4 TRCLK_CKO_GP3 IRQ2_TRFS_GP2 DT_GP1
C25
7 8
CREGVCO
XOSC26N
XOSC26P
DGUARD
12
CREGDIG2
C26
C27
PADDLE
CREGSYNTH
VCOGUARD
C32
9 10
11 12 13 14 15
16
26MHz
09322-044
C29
C30
C32
C34
C35
DR_GP0
C36
C37
Figure 65. Typical ADF7241 Application Circuit Using Antenna Diversity
Rev. 0 | Page 56 of 72
ADF7241
C15 C14 C39 C40 C41 C28
32kHz
VBAT
32 31
30
29 28 27 26
25
PAVSUP_ATB3
XOSC32KN_ATB2
PABIAOP_ATB4
XOSC32KP_GP7_ATB1
CREGDIG1
RXEN_GP6
TXEN_GP5
VDD_BAT
C4 L3 C5
C18
R12
C17
C16 1 2 CREGRF1 RBIAS CREGRF2 RFIO1P RFIO1N RFIO2P RFIO2N CREGRF3
R10 24 CS MOSI SCLK MISO 23 22 21 20 19 18
DSP BFxxx
GPIO1 MOSI SCLK MISO IRQ1IN SPORT SPI
C6 L1
L2
C7
3 4 5 6
ADF7241
IRQ1_GP4 TRCLK_CKO_GP3 IRQ2_TRFS_GP2 DT_GP1
L4 C8 C9 C27
7 8
RCLK
TCLK
17
RFS
CREGSYNTH
VCOGUARD
CREGDIG2
CREGVCO
XOSC26N
XOSC26P
DGUARD
PADDLE
L6 C10
L5
C11
9 10
11
12 13 14 15
16
26MHz
09322-045
C29
C30
C32
C34
C35
DR_GP0
C36
C37
Figure 66. Typical ADF7241 Application Circuit with DSP Using Antenna Diversity
Rev. 0 | Page 57 of 72
DR
DT
ADF7241
C15 C14 C39 C40 C41 C28
32kHz
R14
R15
VBAT 32 31
PABIAOP_ATB4 PAVSUP_ATB3
30
VDD_BAT
29 28 27 26
XOSC32KP_GP7_ATB1 XOSC32KN_ATB2 RXEN_GP6 CREGDIG1
25
TXEN_GP5
R10
C18 C21
ENABLE
R12
C17
C16 1 2 CREGRF1 RBIAS CREGRF2 RFIO1P RFIO1N RFIO2P RFIO2N CREGRF3
24 CS MOSI SCLK MISO 23 22 21
DSP BFxxx
GPIO1 MOSI SCLK MISO IRQ1IN SPORT
RCLK TCLK RFS
GND BALP UNBAL GND BALM 10 C22
LNA
3 4 5 6
SPI
ADF7241
IRQ1_GP4 TRCLK_CKO_GP3 IRQ2_TRFS_GP2 DT_GP1
20 19 18 17
ENABLE
C25 GND BALP UNBAL GND BALM 12 C26 C27
7 8
VCOGUARD
CREGDIG2
PA
CREGSYNTH
CREGVCO
XOSC26N
XOSC26P
DGUARD
PADDLE
9 10
11 12 13 14 15
16
26MHz
09322-075
C29
C30
C32
C34
C35
DR_GP0
C36
C37
Figure 67. Typical ADF7241 Application Circuit with External LNA and External PA
Rev. 0 | Page 58 of 72
DR
DT
C15
C14
C39
C40
C41
C28
32kHz
L7 R14 VBAT R16 32 31 30 29 28 27 26 25
SENSOR SCS MOSI SCLK MISO
R10
CREGDIG1
RXEN_GP6
TXEN_GP5
R12 1 CREGRF1 RBIAS CREGRF2 RFIO1P RFIO1N RFIO2P RFIO2N CREGRF3 2
VDD_BAT
C18 C21 GND UNBAL GND 4 5 6 C25 GND 8 12 C26 C27 UNBAL GND BALM BALP 7 BALM 10 C22 3 BALP
C17
C16
MICROCONTROLLER GPIO0 CSN MOSI SCLK MISO 24 23 22 21 GPIO1 MOSI SCLK MISO
PABIAOP_ATB4
PAVSUP_ATB3
XOSC32KP_GP7_ATB1
ENABLE
XOSC32KN_ATB2
ADF7241
IRQ1_GP4 TRCLK_CKO_GP3 IRQ2_TRFS_GP2 DT_GP1
20 19 18 17
PADDLE
CREGVCO
VCOGUARD
CREGSYNTH
XOSC26P
XOSC26N
DGUARD
CREGDIG2
09322-076
Figure 68. Typical ADF7241 Application Circuit with Discrete External PA
9 10
11 12 13 14 15
16
26MHz
C29
C30
C32
C34
C35
DR_GP0
Rev. 0 | Page 59 of 72
IRQ1IN IRQ2IN
GaAs pHEMT FET
C36
C37
ADF7241
ADF7241 REGISTER MAP
It is recommended that configuration registers be programmed in the idle state. Note that all registers that include fields that are denoted as RC_CONTROLLED must be programmed in the idle state only. Reset values are shown in decimal notation. Table 30. Register Map Overview
Address 0x100 0x105 0x106 0x107 0x108 0x109 0x10A 0x10B 0x13E 0x300 0x301 0x302 0x306 0x30C 0x30D 0x313 0x314 0x315 0x316 0x317 0x318 0x319 0x31A 0x31B 0x31E 0x32C 0x32D 0x33D 0x353 0x354 0x355 0x36E 0x36F 0x371 0x380 0x381 0x395 0x396 0x39B 0x3A7 0x3A8 0x3A9 0x3AA 0x3AE 0x3B9 0x3C7 Register Name ext_ctrl cca1 cca2 buffercfg pkt_cfg delaycfg0 delaycfg1 delaycfg2 rc_cfg ch_freq0 ch_freq1 ch_freq2 tx_m rrb lrb prampg txpb rxpb tmr_cfg0 tmr_cfg1 tmr_rld0 tmr_rld1 tmr_ctrl wuc_32khzosc_status pd_aux gp_cfg gp_out rc_cal_cfg vco_band_ovrw vco_idac_ovrw vco_ovwr_cfg pa_bias vco_cal_cfg xto26_trim_cal vco_band_rb vco_idac_rb rxcal0 rxcal1 rxfe_cfg pa_rr pa_cfg extpa_cfg extpa_msc adc_rbk agc_cfg5 irq1_en0 Access Mode R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R R R/W R/W R/W R/W R/W R/W R/W R/W R R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R R R/W R/W R/W R/W R/W R/W R/W R R/W R/W Description External LNA/PA and internal PA control configuration bits RSSI threshold for CCA CCA mode configuration RX and TX buffer configuration Firmware download module enable and FCS control RC_RX command to SFD search delay RC_TX command to TX state delay MAC delay extension Packet/SPORT mode configuration Channel frequency settings--low byte Channel frequency settings--middle byte Channel frequency settings--two MSBs Preemphasis filter configuration RSSI readback register Signal quality indicator quality readback register PRAM page Transmit packet storage base address Receive packet storage base address Wake-up timer configuration register--high byte Wake-up timer configuration register--low byte Wake-up timer value register--high byte Wake-up timer value register--low byte Wake-up timer timeout flag configuration register 32 kHz oscillator/WUC status Battery monitor and external PA bias enable GPIO configuration GPIO configuration RC calibration setting Overwrite value for the VCO frequency band Overwrite value for the VCO bias current DAC VCO calibration settings overwrite enable PA bias control VCO calibration parameters 26 MHz crystal oscillator configuration Readback VCO band after calibration Readback of the VCO bias current DAC after calibration Receiver baseband filter calibration word, LSB Receiver baseband filter calibration word, MSB Receive baseband filter bandwidth and LNA selection PA ramp rate PA output stage current control External PA bias DAC configuration External PA interface circuit configuration ADC readback AGC configuration parameters Interrupt Mask Set Bits[7:0] of Bits[15:0] for IRQ1
Rev. 0 | Page 60 of 72
ADF7241
Address 0x3C8 0x3C9 0x3CA 0x3CB 0x3CC 0x3E3 0x3E6 0x3F0 0x3F4 Register Name irq1_en1 irq2_en0 irq2_en1 irq_src0 irq_src1 gp_drv bm_cfg tx_test sfd_15_4 Access Mode R/W R/W R/W R/W R/W R/W R/W R/W R/W Description Interrupt Mask Set Bits[15:8] of [15:0] for IRQ1 Interrupt Mask Set Bits[7:0] of [15:0] for IRQ2 Interrupt Mask Set Bits[15:8] of [15:0] for IRQ2 Interrupt Source Bits[7:0] of [15:0] for IRQ Interrupt Source Bits[15:8] of [15:0] for IRQ GPIO and SPI I/O pads drive strength configuration Battery monitor threshold voltage setting TX test mode configuration Option to set nonstandard SFD
Table 31. 0x100: ext_ctrl
Bit [7] Field Name pa_shutdown_mode R/W R/W Reset Value 0 Description PA shutdown mode. 0: fast ramp-down. 1: user defined ramp-down. Reserved, set to default. 1: RXEN_GP6 is set high while in the RX state; otherwise, it is low. 0: RXEN_GP6 is under user control (refer to Register gp_out); refer to Register gp_cfg for restrictions 1: TXEN_GP5 is set high while in the TX state; otherwise, it is low. 0: TXEN_GP5 is under user control (refer to Register gp_out); refer to Register gp_cfg for restrictions. 1: RC enables external PA controller while in the TX state. 0: Register pd_aux, Bit extpa_bias_en (0x31E[4]) is under user control. Reserved, set to default.
[6:5] 4
Reserved rxen_en
R/W R/W
0 0
3
txen_en
R/W
0
2 [1:0]
extpa_auto_en Reserved
R/W R/W
0 0
Table 32. 0x105: cca1
Bit [7:0] Field Name cca_thres R/W R/W Reset Value 171 Description RSSI threshold for CCA. Signed twos complement notation (in dBm). When CCA is completed: Status Word CCA_RESULT = 1 if Register rrb, Bit rssi_readback (0x30C[7:0]) < cca_thres Status Word CCA_RESULT = 0 if Register rrb, Bit rssi_readback (0x30C[7:0]) cca_thres
Table 33. 0x106: cca2
Bit [7:3] 2 1 0 Field Name Reserved continuous_cca rx_auto_cca Reserved R/W R/W R/W R/W R/W Reset Value 0 0 0 0 Description Reserved, set to default. 0: continuous CCA off. 1: generate a CCA interrupt every 128 s. 0: automatic CCA off. 1: generate a CCA interrupt 128 s after entering the RX state. Reserved, set to default.
Rev. 0 | Page 61 of 72
ADF7241
Table 34. 0x107: buffercfg
Bit 7 6 [5:4] Field Name trx_mac_delay Reserved tx_buffer_mode R/W R/W R/W RW Reset Value 0 0 0 Description 0: tx_mac_delay (0x10A[7:0]) and rx_mac_delay (0x109[7:0]) enabled. 1: tx_mac_delay (0x10A[7:0]) and rx_mac_delay (0x109[7:0]) disabled. Reserved, set to default. 0: return to PHY_RDY after frame in TX_BUFFER is transmitted once. 1: cyclic transmission of frame in TX_BUFFER after TX MAC delay with PA ramp-up/down between packets. 2: reserved. 3: cyclic transmission of frame in TX_BUFFER after TX MAC delay with PA kept on. 0: as per tx_buffer_mode setting. 1: automatically goes to RX after TX data transmitted. 0: as per rx_buffer_mode setting. 1: automatically goes to TX after RX packet received. 0: first frame following a RC_RX command is stored in RX_BUFFER; device returns to PHY_RDY state after reception of first frame. 1: continuous reception of frames enabled; a new frame overwrites previous frame. 2: new frames not written to buffer. 3: reserved.
3 2 [1:0]
auto_tx_to_rx_turnaround auto_rx_to_tx_turnaround rx_buffer_mode
R//W R/W R/W
0 0 0
Table 35. 0x108: pkt_cfg
Bit [7:5] 4 Field Name Reserved addon_en R/W R/W R/W Reset Value 0 0 Description Reserved, set to default. 0: firmware add-on module disabled. 1: firmware add-on module enabled; module must be loaded prior to setting this bit. 0: the RF frequency synthesizer calibration and settling phase is performed. 1: skip the RF frequency synthesizer calibration and settling phase. This must only be used when the continuous packet transmission mode is enabled. Refer to the WUC Configuration and Operation section. Reserved, set to default. The rx_pkt_rcvd interrupt is asserted. 0: receive operation--FCS automatically validated; FCS replaced with RSSI and SQI values in RX_BUFFER. Transmit operation--FCS automatically appended to transmitted packet; FCS field in TX_BUFFER is ignored. 1: receive operation--received FCS is stored in RX_BUFFER without validation. Transmit operation--FCS field in TX_BUFFER is transmitted.
3
skip_synt_settle
R/W
0
[2:1] 0
Reserved auto_fcs_off
R/W R/W
2 0
Table 36. 0x109: delaycfg0
Bit [7:0] Field Name rx_mac_delay R/W R/W Reset Value 192 Description Programmable delay from issue of RC_RX command to SFD search and for start of RSSI measurement window.
Table 37. 0x10A: delaycfg1
Bit [7:0] Field Name tx_mac_delay R/W R/W Reset Value 192 Description Programmable delay from issue of RC_TX command to entering the TX state. Programmable in steps of 1 s in both modes.
Rev. 0 | Page 62 of 72
ADF7241
Table 38. 0x10B: delaycfg2
Bit [7:0] Field Name mac_delay_ext R/W R/W Reset Value 0 Description Programmable MAC delay extension. Programmable in steps of 4 s. Applies in both the RX and TX states.
Table 39. 0x13E: rc_cfg
Bit [7:0] Field Name rc_mode R/W R/W Reset Value 0 Description Configure packet format: 0: IEEE 802.15.4-2006 packet mode. 1: reserved. 2: IEEE 802.15.4-2006 receive SPORT mode. 3: IEEE 802.15.4-2006 transmit SPORT mode. 4, 5 to 255: reserved.
Table 40. 0x300: ch_freq0
Bit [7:0] Field Name ch_freq[7:0] R/W R/W Reset Value 128 Description Channel frequency [Hz]/10 kHz, Bits[7:0] of Bits[23:0].
Table 41. 0x301: ch_freq1
Bit [7:0] Field Name ch_freq[15:8] R/W R/W Reset Value 169 Description Channel frequency [Hz]/10 kHz, Bits[15:8] of Bits[23:0].
Table 42. 0x302: ch_freq2
Bit [7:0] Field Name ch_freq[23:16] R/W R/W Reset Value 3 Description Channel frequency [Hz]/10 kHz, Bits[23:16] of Bits[23:0].
Table 43. 0x306: tx_m
Bit [7:1] 0 Field Name RC_CONTROLLED preemp_filt R/W R/W R/W Reset Value 0 1 Description Controlled by radio controller. 1: enable; 0: disable preemphasis filter.
Table 44. 0x30C: rrb
Bit [7:0] Field Name rssi_readback R/W R Reset Value 0 Description Receive input power in dBm; signed twos complement.
Table 45. 0x30D: lrb
Bit [7:0] Field Name sqi_readback R/W R Reset Value 0 Description Signal quality indicator readback value.
Table 46. 0x313: prampg
Bit [7:4] [3:0] Field Name Reserved pram_page R/W R/W R/W Reset Value 0 0 Description Reserved, set to default. Program PRAM page.
Rev. 0 | Page 63 of 72
ADF7241
Table 47. 0x314: txpb
Bit [7:0] Field Name tx_pkt_base R/W R/W Reset Value 128 Description Base address of TX_BUFFER in packet RAM.
Table 48. 0x315: rxpb
Bit [7:0] Field Name rx_pkt_base R/W R/W Reset Value 0 Description Base address of RX_BUFFER in packet RAM.
Table 49. 0x316: tmr_cfg0
Bit [7:3] [2:0] Field Name Reserved timer_prescal R/W R/W R/W Reset Value 0 0 Description Reserved, set to default. Divider factor for XTO32K or RCO. 0: /1. 1: /4. 2: /8. 3: /16. 4: /128. 5: /1024. 6: /8192. 7: /65,536. Note that this is a write-only register and should be written to prior to writing to Register tmr_cfg1. Settings become effective only after writing to Register tmr_cfg1.
Table 50. 0x317: tmr_cfg1
Bit 7 [6:3] Field Name Reserved sleep_config R/W R/W R/W Reset Value 0 0 Description Reserved, set to default. 1: SLEEP_BBRAM. 4: SLEEP_XTO.
5: SLEEP_BBRAM_XTO.
[2:1] 0
Reserved wake_on_timeout
R/W R/W
0 0
11: SLEEP_BBRAM_RCO. 0, 2, 3, 6 to 10, 12 to 15: reserved. Refer to note in Register tmr_cfg0. Reserved, set to default. 1: enable, 0: disable wake-up on timeout event.
Table 51. 0x318: tmr_rld0
Bit [7:0] Field Name timer_reload[15:8] R/W R/W Reset Value 0 Description Timer reload value, Bits[15:8] of Bits[15:0]. Note that this is a write-only register and should be written to prior to writing to Register tmr_rld1. Settings become effective only after writing to Register tmr_rld1.
Table 52. 0x319: tmr_rld1
Bit [7:0] Field Name timer_reload[7:0] R/W R/W Reset Value 0 Description Timer reload value, Bits[7:0] of Bits[15:0]. Refer to note in Register tmr_rld0.
Rev. 0 | Page 64 of 72
ADF7241
Table 53. 0x31A: tmr_ctrl
Bit [7:2] 1 0 Field Name Reserved wuc_rc_osc_cal wake_timer_flag_reset R/W R/W R/W R/W Reset Value 0 0 0 Description Reserved, set to default. 1: enable. 0: disable 32 kHz RC oscillator calibration. Timer flag reset. 0: normal operation. 1: reset Field wuc_tmr_prim_toflag and Field wuc_porflag (0x31B).
Table 54. 0x31B: wuc_32khzosc_status
Bit [7:6] 5 Field Name Reserved rc_osc_cal_ready R/W R R Reset Value 0 0 Description Reserved, set to default. 32 kHz RC oscillator calibration (only valid if wuc_rc_osc_cal = 1). Calibration takes 1 ms. 0: calibration in progress. 1: calibration finished. 32 kHz crystal oscillator (only valid if sleep_config (0x317[6:3]) = 4 or 5). 0: oscillator not settled. 1: oscillator has settled. Reserved, set to default. Chip cold start event registration. 0: not registered. 1: registered. WUC timeout event registration (the output of a latch triggered by a timeout event). 0: not registered. 1: registered. Reserved, set to default.
4
xosc32_ready
R
0
3 2
Reserved wuc_porflag
R R
0 0
1
wuc_tmr_prim_toflag
R
0
0
Reserved
R
0
Table 55. 0x31E: pd_aux
Bit 7 6 5 4 Field Name Reserved RC_CONTROLLED battmon_en extpa_bias_en R/W R/W R/W R/W R/W Reset Value 0 0 0 0 Description Reserved, set to default. Controlled by radio controller. 1: enable. 0: disable battery monitor. 1: enable. 0: disable external PA biasing circuit. Controlled by radio controller when Register ext_ctrl, Field extpa_auto_en = 1 (0x100[2]). Controlled by radio controller.
[3:0]
RC_CONTROLLED
R/W
0
Table 56. 0x32C: gp_cfg
Bit [7:0] Field Name gpio_config R/W R/W Reset Value 0 Description 0: IRQ1, IRQ2 functionality. Register gp_out, Bit gpio_dout[6] controls RXEN output. Register gp_out, Bit gpio_dout[5] controls TXEN output. 1: TRCLK and data pins active in RX, gated by synchronization word detection. 1, 4: TRCLK and data pins active in TX. 7: symbol clock output on TRCLK pin and symbol data output on GP6, GP5, GP1, and GP0. Refer to Table 19 for further details of SPORT mode configurations. 2, 3, 5, 6, 8 to 255: reserved.
Rev. 0 | Page 65 of 72
ADF7241
Table 57. 0x32D: gp_out
Bit [7:0] Field Name gpio_dout R/W R/W Reset Value 0 Description GPIO output value if Register gp_cfg, Field gpio_config = 4. gpio_dout[7:0] = GP7 to GP0. If Register ext_ctrl, Field rxen_en = 1, then Register gp_out, Bit gpio_dout[6] is controlled by radio controller. If Register ext_ctrl, Field txen_en = 1, then Register gp_out, Bit gpio_dout[5] is controlled by radio controller.
Table 58. 0x33D: rc_cal_cfg
Bit [7:2] [1:0] Field Name Reserved skip_rc_cal R/W R/W R/W Reset Value 15 0 Description Reserved, set to default. 0: do not skip RC calibration. This calibration is performed only when transitioning from idle to PHY_RDY. 3: skip RC calibration.
Table 59. 0x353: vco_band_ovrw
Bit [7:0] Field Name vco_band_ovrw_val R/W R/W Reset Value 0 Description Overwrite value for the VCO frequency band. Enabled when vco_band_ovrw_en = 1 and Register vco_cal_cfg, Field skip_vco_cal = 15.
Table 60. 0x354: vco_idac_ovrw
Bit [7:0] Field Name vco_idac_ovrw_val R/W R/W Reset Value 0 Description Overwrite value for the VCO bias current DAC. Enabled when Register vco_cal_cfg, Field skip_vco_cal = 15 and Field vco_idac_ovrw_en = 1.
Table 61. 0x355: vco_ovrw_cfg
Bit [7:2] 1 Field Name Reserved vco_idac_ovrw_en R/W R/W R/W Reset Value 2 0 Description Reserved, set to default. VCO bias current DAC overwrite. Effective only if Register vco_cal_cfg, Field skip_vco_cal = 15. 0: disable. 1: enable. VCO frequency band overwrite. Effective only if Register vco_cal_cfg, Field skip_vco_cal = 15. 0: disable. 1: enable.
0
vco_band_ovrw_en
R/W
0
Table 62. 0x36E: pa_bias
Bit 7 [6:1] 0 Field Name Reserved pa_bias_ctrl Reserved R/W R/W R/W R/W Reset Value 0 55 1 Description Reserved, set to default. Set to 63 if maximum PA output power of 4.8 dBm is required. Reserved, set to default.
Table 63. 0x36F: vco_cal_cfg
Bit [7:4] [3:0] Field Name Reserved skip_vco_cal R/W R/W R/W Reset Value 0 9 Description Reserved, set to default. 9: do not skip VCO calibration. 15: skip VCO calibration.
Rev. 0 | Page 66 of 72
ADF7241
Table 64. 0x371: xto26_trim_cal
Bit [7:6] [5:3] Field Name Reserved xto26_trim R/W R/W R/W Reset Value 0 4 Description Reserved, set to default. 26 MHz crystal oscillator (XOSC26N ) tuning capacitor control word. The load capacitance is adjusted according to the value of xto26_trim as follows: 0: -4 x 187.5 fF. 1: -3 x 187.5 fF. 2: -2 x 187.5 fF. 3: -1 x 187.5 fF. 4: 0 x 187.5 fF. 5: 1 x 187.5 fF. 6: 2 x 187.5 fF. 7: 3 x 187.5 fF. Reserved, set to default.
[2:0]
Reserved
R/W
0
Table 65. 0x381: vco_band_rb
Bit [7:2] Field Name vco_band_val_rb R/W R Reset Value 0 Description Readback for the VCO frequency band after calibration.
Table 66. 0x381: vco_idac_rb
Bit [7:2] Field Name vco_idac_val_rb R/W R Reset Value 0 Description Readback of the VCO bias current DAC after calibration.
Table 67. 0x395: rxcal0
Bit [7:0] Field Name dcap_ovwrt_low R/W R/W Reset Value 0 Description RXBB filter tuning overwrite word, LSB.
Table 68. 0x396: rxcal1
Bit [7:2] 1 0 Field Name Reserved dcap_ovwrt_en dcap_ovwrt_high R/W R/W R/W R/W Reset Value 2 0 0 Description Reserved, set to default. RXBB filter tuning overwrite word enable. RXBB filter tuning overwrite word, MSB.
Table 69. 0x39B: rxfe_cfg
Bit [7:5] 4 Field Name Reserved lna_sel R/W R/W R/W Reset Value 0 1 Description Reserved, set to default. Receive: 0: use LNA1. 1: use LNA2. Reserved, set to default.
[3:0]
Reserved
R/W
13
Table 70. 0x3A7: pa_rr
Bit [7:3] [2:0] Field Name Reserved pa_ramp_rate R/W R/W R/W Reset Value 0 7 Description Reserved, set to default. PA ramp rate: 2pa_ramp_rate x 2.4 ns per PA power step.
Rev. 0 | Page 67 of 72
ADF7241
Table 71. 0x3A8: pa_cfg
Bit 7 [6:5] [4:0] Field Name Reserved Reserved pa_bridge_dbias R/W R/W R/W R/W Reset Value 0 0 13 Description Reserved, set to default. Set to default. Set to 21 if output power of 4.8 dBm is required from PA.
Table 72. 0x3A9: extpa_cfg
Bit [7:5] [4:0] Field Name Reserved extpa_bias R/W R/W R/W Reset Value 0 0 Description Reserved, set to default. If Register extpa_msc, Field extpa_bias_mode = 1, 2, 3, or 4, PABIAOP_ATB4 pin DAC current = 80 A - 2.58 A x extpa_bias. If Register extpa_msc, Field extpa_bias_mode = 5 or 6, PAVSUP_ATB3 pin servo current set point = 22 mA - 0.349 mA x extpa_bias.
Table 73. 0x3AA: extpa_msc
Bit [7:4] Field Name pa_pwr R/W R/W Reset Value 15 Description PA output power after ramping phase: 3: minimum power. 15: maximum power. Nominal power step size 2 dB per LSB. 0: select RBIAS-referred reference current. 1: select band gap-referred reference current. External PA interface configuration: 0: PAVSUP_ATB3 = on; PABIAOP_ATB4 = floating. 1: PAVSUP_ATB3 = on; PABIAOP_ATB4 = current source. 2: PAVSUP_ATB3 = on; PABIAOP_ATB4 = current sink. 3: PAVSUP_ATB3 = off; PABIAOP_ATB4 = current source. 4: PAVSUP_ATB3 = off; PABIAOP_ATB4 = current sink. 5: PAVSUP_ATB3 = on; PABIAOP_ATB4 = positive servo output. 6: PAVSUP_ATB3 = on; PABIAOP_ATB4 = negative servo output. 7: reserved.
3 [2:0]
extpa_bias_src extpa_bias_mode
R/W R/W
0 1
Table 74. 0x3AE: adc_rbk
Bit [7:6] [5:0] Field Name Reserved adc_out R/W R R Reset Value 0 0 Description Ignore. ADC output code.
Table 75. 0x3B9: agc_cfg5
Bit [7:5] [4:2] [1:0] Field Name Reserved rssi_offs Reserved R/W R/W R/W R/W Reset Value 0 4 3 Description Set to 0. RSSI offset adjust, rssi_offs is added to Register rrb, Field rssi_readback. Reserved, set to default.
Table 76. 0x3C7: irq1_en0
Bit 7 6 5 4 3 2 1 0 Field Name Reserved Reserved batt_alert por rc_ready wakeup powerup Reserved R/W R/W R/W R/W R/W R/W R/W R/W R/W Reset Value 0 0 0 0 0 0 1 0 Description Set to 0. Set to 0. Battery monitor interrupt. Power-on reset event. Radio controller ready to accept new command. Timer has timed out. Chip is ready for access. Set to 0.
Rev. 0 | Page 68 of 72
ADF7241
Table 77. 0x3C8: irq1_en1
Bit 7 6 5 4 3 2 1 0 Field Name Reserved Reserved Reserved tx_pkt_sent rx_pkt_rcvd tx_sfd rx_sfd cca_complete R/W R/W R/W R/W R/W R/W R/W R/W R/W Reset Value 0 0 0 0 0 0 0 0 Description Set to 0. Set to 0. Set to 0. Packet transmission complete. Packet received in RX_BUFFER. SFD was transmitted. SFD was detected. CCA_RESULT in status word is valid.
Table 78. 0x3C9: irq2_en0
Bit 7 6 5 4 3 2 1 0 Field Name Reserved Reserved batt_alert por rc_ready wakeup powerup Reserved R/W R/W R/W R/W R/W R/W R/W R/W R/W Reset Value 0 0 0 0 0 0 1 0 Description Set to 0. Set to 0. Battery monitor interrupt. Power-on reset event. Radio controller ready to accept new command. Timer has timed out. Chip is ready for access. Set to 0.
Table 79. 0x3CA: irq2_en1
Bit 7 6 5 4 3 2 1 0 Field Name Reserved Reserved Reserved tx_pkt_sent rx_pkt_rcvd tx_sfd rx_sfd cca_complete R/W R/W R/W R/W R/W R/W R/W R/W R/W Reset Value 0 0 0 0 0 0 0 0 Description Set to 0. Set to 0. Set to 0. Packet transmission complete. Packet received in RX_BUFFER. SFD was transmitted. SFD was detected. CCA_RESULT in status word is valid.
Table 80. 0x3CB: irq_src0
Bit 7 6 5 4 3 2 1 0 Field Name Reserved Reserved batt_alert por rc_ready wakeup powerup Reserved R/W R/W R/W R/W R/W R/W R/W R/W R/W Reset Value 0 0 0 0 0 0 0 0 Description Set to 0. Set to 0. Battery monitor interrupt. Power-on reset event. Radio controller ready to accept new command. Timer has timed out. Chip is ready for access. Set to 0.
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ADF7241
Table 81. 0x3CC: irq_src1
Bit 7 6 5 4 3 2 1 0 Field Name Reserved Reserved Reserved tx_pkt_sent rx_pkt_rcvd tx_sfd rx_sfd cca_complete R/W R/W R/W R/W R/W R/W R/W R/W R/W Reset Value 0 0 0 0 0 0 0 0 Description Set to 0. Set to 0. Set to 0. Packet transmission complete. Packet received in RX_BUFFER. SFD was transmitted. SFD was detected. CCA_RESULT in status word is valid.
Table 82. 0x3E3: gp_drv
Bit [7:4] [3:2] Field Name Reserved gpio_slew R/W R/W R/W Reset Value 0 0 Description Reserved, set to default. GPIO and SPI slew rate. 0: very slow. 1: slow. 2: very fast. 3: fast. GPIO and SPI drive strength. 0: 4 mA. 1: 8 mA. 2: >8 mA. 3: reserved.
[1:0]
gpio_drive
R/W
0
Table 83. 0x3E6: bm_cfg
Bit 7:5] [4:0] Field Name Reserved battmon_voltage R/W R/W R/W Reset Value 0 0 Description Reserved, set to default. Battery monitor trip voltage: 1.7 V + 62 mV x battmon_voltage; the batt_alert interrupt is asserted when VDD_BAT drops below the trip voltage.
Table 84. 0x3F0: tx_test
Bit [7:2] 1 0 Field Name Reserved carrier_only Reserved R/W R/W R/W R/W Reset Value 2 0 0 Description Reserved, set to default. Transmits unmodulated tone at the programmed frequency fCH. Reserved, set to default.
Table 85. 0x3F4: sfd_15_4
Bit [7:4] [3:0] Field Name sfd_symbol_2 sfd_symbol_1 R/W R/W R/W Reset Value 10 7 Description Symbol 2 of SFD note: IEEE 802.15.4-2006 requires SFD1 = 10. Symbol 1 of SFD note: IEEE 802.15.4-2006 requires SFD1 = 7.
Rev. 0 | Page 70 of 72
ADF7241 OUTLINE DIMENSIONS
PIN 1 INDICATOR 5.10 5.00 SQ 4.90 0.30 0.25 0.18
25 24 32 1
PIN 1 INDICATOR
0.50 BSC
EXPOSED PAD
3.45 3.30 SQ 3.15
17
8 16 9
TOP VIEW 0.80 0.75 0.70
0.50 0.40 0.30
BOTTOM VIEW
0.25 MIN
SEATING PLANE
0.05 MAX 0.02 NOM COPLANARITY 0.08 0.20 REF
FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET.
COMPLIANT TO JEDEC STANDARDS MO-220-WHHD.
Figure 69. 32-Lead Lead Frame Chip Scale Package [LFCSP_WQ] 5 mm x 5 mm Body, Very Thin Quad (CP-32-13) Dimensions shown in millimeters
ORDERING GUIDE
Model 1 ADF7241BCPZ ADF7241BCPZ-RL7 EVAL-ADF7241DB1Z EVAL-ADF7XXXMB3Z
1
Temperature Range -40C to +85C -40C to +85C
Package Description 32-Lead Lead Frame Chip Scale Package [LFCSP_WQ] 32-Lead Lead Frame Chip Scale Package [LFCSP_WQ] Evaluation Platform Daughterboard Evaluation Platform Motherboard
033009-A
Package Option CP-32-13 CP-32-13
Z = RoHS Compliant Part.
Rev. 0 | Page 71 of 72
ADF7241 NOTES
(c)2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D09322-0-1/11(0)
Rev. 0 | Page 72 of 72

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