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E2O0017-27-X2
Semiconductor MSM82C51A-2RS/GS/JS
Semiconductor
This version: Jan. 1998 MSM82C51A-2RS/GS/JS Previous version: Aug. 1996
UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER
GENERAL DESCRIPTION
The MSM82C51A-2 is a USART (Universal Synchronous Asynchronous Receiver Transmitter) for serial data communication. As a peripheral device of a microcomputer system, the MSM82C51A-2 receives parallel data from the CPU and transmits serial data after conversion. This device also receives serial data from the outside and transmits parallel data to the CPU after conversion. The MSM82C51A-2 configures a fully static circuit using silicon gate CMOS technology. Therefore, it operates on extremely low power at 100 mA (max) of standby current by suspending all operations.
FEATURES
* Wide power supply voltage range from 3 V to 6 V * Wide temperature range from -40C to 85C * Synchronous communication upto 64 Kbaud * Asynchronous communication upto 38.4 Kbaud * Transmitting/receiving operations under double buffered configuration. * Error detection (parity, overrun and framing) * 28-pin Plastic DIP (DIP28-P-600-2.54): (Product name: MSM82C51A-2RS) * 28-pin Plastic QFJ (QFJ28-P-S450-1.27): (Product name: MSM82C51A-2JS) * 32-pin Plastic SSOP(SSOP32-P-430-1.00-K): (Product name: MSM82C51A-2GS-K)
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Semiconductor
MSM82C51A-2RS/GS/JS
FUNCTIONAL BLOCK DIAGRAM
D7 - D0
Data Bus Buffer
Transmit Buffer (P - S)
TXD
DSR DTR CTS RTS
Internal Bus Line
RESET CLK C/D RD WR CS
Read/Write Control Logic
Transmit Control
TXRDY TXE TXC
Modem Control
Recieve Buffer (S - P)
RXD
Recieve Control
RXRDY RXC SYNDET/BD
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Semiconductor
MSM82C51A-2RS/GS/JS
PIN CONFIGURATION (TOP VIEW)
28 pin Plastic DIP
D2 D3 RXD GND D4 D5 D6 D7 TXC 1 2 3 4 5 6 7 8 9 28 D1 27 D0 26 VCC 25 RXC 24 DTR 23 RTS 22 DSR 21 RESET 20 CLK 19 TXD 18 TXEMPTY 17 CTS 16 SYNDET/BD 15 TXRDY
28 pin Plastic QFJ
4 GND 3 RXD 26 VCC 27 D0 2 D3 1 D2 28 D1
WR 10 CS 11 C/D 12 RD 13 RXRDY 14 25 RXC 24 DTR 23 RTS 22 DSR 21 RESET 20 CLK 19 TXD D2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
D4 D5 D6 D7 TXC
5 6 7 8 9
WR 10 CS 11
C/D 12 RD 13 RXRDY 14 TXRDY 15 SYNDET/BD 16 CTS 17 18
32 pin Plastic SSOP
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 D1 D0 VCC NC RXC DTR RTS DSR RESET CLK TXD TXEMPTY NC CTS SYNDET/BD TXRDY
D3 RXD NC GND D4 D5 D6 D7 TXC WR CS NC C/D RD RXRDY
TXEMPTY
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Semiconductor
MSM82C51A-2RS/GS/JS
FUNCTION
Outline The MSM82C51A-2's functional configuration is programed by software. Operation between the MSM82C51A-2 and a CPU is executed by program control. Table 1 shows the operation between a CPU and the device.
Table 1 Operation between MSM82C51A and CPU CS 1 0 0 0 0 0 C/D 1 1 0 0 RD 1 0 1 0 1 WR 1 1 0 1 0 Data Bus 3-State Data Bus 3-State Status AE CPU Control Word CPU Data AE CPU Data CPU
It is necessary to execute a function-setting sequence after resetting the MSM82C51A-2. Fig. 1 shows the function-setting sequence. If the function was set, the device is ready to receive a command, thus enabling the transfer of data by setting a necessary command, reading a status and reading/writing data.
External Reset Internal Reset Write Mode Instruction
Asynchronous no Write First Sync Charactor
yes
Single Sync Mode no Write Second Sync Charactor
yes
End of Mode Setting
Fig. 1 Function-setting Sequence (Mode Instruction Sequence)
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Semiconductor Control Words There are two types of control word. 1. Mode instruction (setting of function) 2. Command (setting of operation)
MSM82C51A-2RS/GS/JS
1) Mode Instruction Mode instruction is used for setting the function of the MSM82C51A-2. Mode instruction will be in "wait for write" at either internal reset or external reset. That is, the writing of a control word after resetting will be recognized as a "mode instruction." Items set by mode instruction are as follows: * * * * * * * Synchronous/asynchronous mode Stop bit length (asynchronous mode) Character length Parity bit Baud rate factor (asynchronous mode) Internal/external synchronization (synchronous mode) Number of synchronous characters (Synchronous mode)
The bit configuration of mode instruction is shown in Figures 2 and 3. In the case of synchronous mode, it is necessary to write one-or two byte sync characters. If sync characters were written, a function will be set because the writing of sync characters constitutes part of mode instruction.
D7 S1 D6 S1 D5 EP D4 PEN D3 L2 D2 L1 D1 B2 D0 B1 Baud Rate Factor 0 0 Refer to Fig. 3 SYNC 1 0 1 0 1 16 1 1 64
Charactor Length 0 0 5 bits 1 0 6 bits 0 1 7 bits 1 1 8 bits
Parity Check 0 0 Disable 1 0 Odd Parity 0 1 Disable 1 1 Even Parity
Stop bit Length 0 0 Inhabit 1 0 1 bit 0 1 1.5 bits 1 1 2 bits
Fig. 2 Bit Configuration of Mode Instruction (Asynchronous)
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Semiconductor
MSM82C51A-2RS/GS/JS
D7 SCS
D6 ESD
D5 EP
D4 PEN
D3 L2
D2 L1
D1 0
D0 0 Charactor Length 0 0 5 bits Parity 0 0 Disable 1 0 Odd Parity 0 1 Disable 1 1 Even Parity 1 0 6 bits 0 1 7 bits 1 1 8 bits
Synchronous Mode 0 Internal Synchronization 1 External Synchronization
Number of Synchronous Charactors 0 2 Charactors 1 1 Charactor
Fig. 3 Bit Configuration of Mode Instruction (Synchronous)
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Semiconductor 2) Command
MSM82C51A-2RS/GS/JS
Command is used for setting the operation of the MSM82C51A-2. It is possible to write a command whenever necessary after writing a mode instruction and sync characters. Items to be set by command are as follows: * * * * * * * Transmit Enable/Disable Receive Enable/Disable DTR, RTS Output of data. Resetting of error flag. Sending to break characters Internal resetting Hunt mode (synchronous mode)
The bit configuration of a command is shown in Fig. 4.
D7 EH D6 IR D5 RTS D4 ER D3 SBRK D2 RXE D1 DTR D0 TXEN 1Transmit Enable 0Disable DTR 1 AE DTR = 0 0 AE DTR = 1 1Recieve Enable 0Disable 1Sent Break Charactor 0Normal Operation 1Reset Error Flag 0Normal Operation RTS 1 AE RTS = 0 0 AE RTS = 1 1Internal Reset 0Normal Operation 1Hunt Mode (Note) 0Normal Operation Note: Seach mode for synchronous charactors in synchronous mode. Fig. 4 Bit Configuration of Command
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Semiconductor Status Word
MSM82C51A-2RS/GS/JS
It is possible to see the internal status of MSM82C51A-2 by reading a status word. The bit configuration of status word is shown in Fig. 5.
D7 DSR D6
SYNDET /BD
D5 FE
D4 OE
D3 PE
D2
TXEMPTY
D1
RXRDY
D0
TXRDY
Parity Different from TXRDY Terminal. Refer to "Explanation" of TXRDY Terminals. Same as terminal. Refer to "Explanation" of Terminals. 1Parity Error
1Overrun Error
1Framing Error Note: Only asynchronous mode. Stop bit cannot be detected. Shows Terminal DSR 1DSR = 0 0DSR = 1
Fig. 5 Bit Configuration of Status Word
Standby Status It is possible to put the MSM82C51A-2 in "standby status" When the following conditions have been satisfied the MSM82C51A-2 is in "standby status." (1) CS terminal is fixed at Vcc level. (2) Input pins other CS , D0 to D7, RD, WR and C/D are fixed at Vcc or GND level (including SYNDET in external synchronous mode). Note: When all output currents are 0, ICCS specification is applied.
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Semiconductor Pin Description
MSM82C51A-2RS/GS/JS
D0 to D7 (l/O terminal) This is bidirectional data bus which receive control words and transmits data from the CPU and sends status words and received data to CPU. RESET (Input terminal) A "High" on this input forces the MSM82C51A-2 into "reset status." The device waits for the writing of "mode instruction." The min. reset width is six clock inputs during the operating status of CLK. CLK (Input terminal) CLK signal is used to generate internal device timing. CLK signal is independent of RXC or TXC. However, the frequency of CLK must be greater than 30 times the RXC and TXC at Synchronous mode and Asynchronous "x1" mode, and must be greater than 5 times at Asynchronous "x16" and "x64" mode. WR (Input terminal) This is the "active low" input terminal which receives a signal for writing transmit data and control words from the CPU into the MSM82C51A-2. RD (Input terminal) This is the "active low" input terminal which receives a signal for reading receive data and status words from the MSM82C51A-2. C/D (Input terminal) This is an input terminal which receives a signal for selecting data or command words and status words when the MSM82C51A-2 is accessed by the CPU. If C/D = low, data will be accessed. If C/D = high, command word or status word will be accessed. CS (Input terminal) This is the "active low" input terminal which selects the MSM82C51A-2 at low level when the CPU accesses. Note: The device won't be in "standby status"; only setting CS = High. Refer to "Explanation of Standby Status." TXD (output terminal) This is an output terminal for transmitting data from which serial-converted data is sent out. The device is in "mark status" (high level) after resetting or during a status when transmit is disabled. It is also possible to set the device in "break status" (low level) by a command.
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Semiconductor
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TXRDY (output terminal) This is an output terminal which indicates that the MSM82C51A-2 is ready to accept a transmitted data character. But the terminal is always at low level if CTS = high or the device was set in "TX disable status" by a command. Note: TXRDY status word indicates that transmit data character is receivable, regardless of CTS or command. If the CPU writes a data character, TXRDY will be reset by the leading edge or WR signal. TXEMPTY (Output terminal) This is an output terminal which indicates that the MSM82C51A-2 has transmitted all the characters and had no data character. In "synchronous mode," the terminal is at high level, if transmit data characters are no longer remaining and sync characters are automatically transmitted. If the CPU writes a data character, TXEMPTY will be reset by the leading edge of WR signal. Note : As the transmitter is disabled by setting CTS "High" or command, data written before disable will be sent out. Then TXD and TXEMPTY will be "High". Even if a data is written after disable, that data is not sent out and TXE will be "High".After the transmitter is enabled, it sent out. (Refer to Timing Chart of Transmitter Control and Flag Timing) TXC (Input terminal) This is a clock input signal which determines the transfer speed of transmitted data. In "synchronous mode," the baud rate will be the same as the frequency of TXC. In "asynchronous mode", it is possible to select the baud rate factor by mode instruction. It can be 1, 1/16 or 1/64 the TXC. The falling edge of TXC sifts the serial data out of the MSM82C51A-2. RXD (input terminal) This is a terminal which receives serial data. RXRDY (Output terminal) This is a terminal which indicates that the MSM82C51A-2 contains a character that is ready to READ. If the CPU reads a data character, RXRDY will be reset by the leading edge of RD signal. Unless the CPU reads a data character before the next one is received completely, the preceding data will be lost. In such a case, an overrun error flag status word will be set. RXC (Input terminal) This is a clock input signal which determines the transfer speed of received data. In "synchronous mode," the baud rate is the same as the frequency of RXC. In "asynchronous mode," it is possible to select the baud rate factor by mode instruction. It can be 1, 1/16, 1/64 the RXC.
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Semiconductor
MSM82C51A-2RS/GS/JS
SYNDET/BD (Input or output terminal) This is a terminal whose function changes according to mode. In "internal synchronous mode." this terminal is at high level, if sync characters are received and synchronized. If a status word is read, the terminal will be reset. In "external synchronous mode, "this is an input terminal. A "High" on this input forces the MSM82C51A-2 to start receiving data characters. In "asynchronous mode," this is an output terminal which generates "high level"output upon the detection of a "break" character if receiver data contains a "low-level" space between the stop bits of two continuous characters. The terminal will be reset, if RXD is at high level. After Reset is active, the terminal will be output at low level. DSR (Input terminal) This is an input port for MODEM interface. The input status of the terminal can be recognized by the CPU reading status words. DTR (Output terminal) This is an output port for MODEM interface. It is possible to set the status of DTR by a command. CTS (Input terminal) This is an input terminal for MODEM interface which is used for controlling a transmit circuit. The terminal controls data transmission if the device is set in "TX Enable" status by a command. Data is transmitable if the terminal is at low level. RTS (Output terminal) This is an output port for MODEM interface. It is possible to set the status RTS by a command.
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Semiconductor
MSM82C51A-2RS/GS/JS
ABSOLUTE MAXIMUM RATING
Parameter Power Supply Voltage Input Voltage Output Voltage Storage Temperature Power Dissipation Symbol VCC VIN VOUT TSTG PD 0.9 Rating
MSM82C51A-2RS MSM82C51A-2GS MSM82C51A-2JS
Unit V V V C 0.9 W
Conditions With respect to GND -- Ta = 25C
-0.5 to +7 -0.5 to VCC +0.5 -0.5 to VCC +0.5 -55 to +150 0.7
OPERATING RANGE
Parameter Power Supply Voltage Operating Temperature Symbol VCC Top Range 3-6 -40 to 85 Unit V C
RECOMMENDED OPERATING CONDITIONS
Parameter Power Supply Voltage Operating Temperature "L" Input Voltage "H" Input Voltage Symbol VCC Top VIL VIH Min. 4.5 -40 -0.3 2.2 Typ. 5 +25 -- -- Max. 5.5 +85 +0.8 VCC +0.3 Unit V C V V
DC CHARACTERISTICS
(VCC = 4.5 to 5.5 V Ta = -40C to +85C) Parameter "L" Output Voltage "H" Output Voltage Input Leak Current Output Leak Current Operating Supply Current Standby Supply Current Symbol VOL VOH ILI ILO ICCO ICCS Min. -- 3.7 -10 -10 -- -- Typ. -- -- -- -- -- -- Max. 0.45 -- 10 10 5 100 Unit V V mA mA mA mA Measurement Conditions IOL = 2.5 mA IOH = -2.5 mA 0 VIN VCC 0 VOUT VCC Asynchronous X64 during Transmitting/ Receiving All Input voltage shall be fixed at VCC or GND level.
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Semiconductor
MSM82C51A-2RS/GS/JS
AC CHARACTERISTICS
CPU Bus Interface Part
(VCC = 4.5 to 5.5 V, Ta = -40 to 85C) Parameter Address Stable before RD Address Hold Time for RD RD Pulse Width Data Delay from RD RD to Data Float Recovery Time between RD Address Stable before WR Address Hold Time for WR WR Pulse Width Data Set-up Time for WR Data Hold Time for WR Recovery Time between WR RESET Pulse Width Symbol tAR tRA tRR tRD tDF tRVR tAW tWA tWW tDW tWD tRVW tRESW Min. 20 20 130 -- 10 6 20 20 100 100 0 6 6 Max. -- -- -- 100 75 -- -- -- -- -- -- -- -- Unit ns ns ns ns ns tCY ns ns ns ns ns tCY tCY Remarks Note 2 Note 2 -- -- -- Note 5 Note 2 Note 2 -- -- -- Note 4 --
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Semiconductor Serial Interface Part
Parameter Main Clock Period Clock Low Tme Clock High Time Clock Rise/Fall Time TXD Delay from Falling Edge of TXC 1 Baud Transmitter Clock Frequency 16 Baud 64 Baud Transmitter Clock Low Time Transmitter Clock High Time 1 Baud 16 , 64 Baud 1 Baud 16 , 64 Baud 1 Baud Receiver Clock Frequency 16 Baud 64 Baud Receiver Clock Low Time Receiver Clock High Time 1 Baud 16 , 64 Baud 1 Baud 16 , 64 Baud Symbol tCY tf tf tr, tf tDTX fTX fTX fTX tTPW tTPW tTPD tTPD fRX fRX fRX tRPW tRPW tRPD tRPD tTXRDY tTXRDY CLEAR tRXRDY tRXRDY CLEAR tIS tES tTXEMPTY tWC tCR tRXDS tRXDH Min. 160 50 70 -- -- DC DC DC 13 2 15 3 DC DC DC 13 2 15 3 -- -- -- -- -- 18 20 8 20 11 17
MSM82C51A-2RS/GS/JS
(VCC = 4.5 to 5.5 V, Ta = -40 to 85C) Max. -- -- tCY -50 20 1 64 615 615 -- -- -- -- 64 615 615 -- -- -- -- 8 400 26 400 26 -- -- -- -- -- -- Unit ns ns ns ns mS kHz kHz kHz tCY tCY tCY tCY kHz kHz kHz tCY tCY tCY tCY tCY ns tCY ns tCY tCY tCY tCY tCY tCY tCY -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- Note 3 -- -- -- -- Note 3 Remarks Note 3 -- -- -- --
Time from the Center of Last Bit to the Rise of TXRDY Time from the Leading Edge of WR to the Fall of TXRDY Time From the Center of Last Bit to the Rise of RXRDY Time from the Leading Edge of RD to the Fall of RXRDY Internal SYNDET Delay Time from Rising Edge of RXC SYNDET Setup Time for RXC TXE Delay Time from the Center of Last Bit MODEM Control Signal Delay Time from Rising Edge of WR MODEM Control Signal Setup Time for Falling Edge of RD RXD Setup Time for Rising Edge of RXC (1X Baud) RXD Hold Time for Falling Edge of RXC (1X Baud)
Notes: 1. AC characteristics are measured at 150 pF capacity load as an output load based on 0.8 V at low level and 2.2 V at high level for output and 1.5 V for input. 2. Addresses are CS and C/D. 3. fTX or fRX 1/(30 Tcy) 1 Baud fTX or fRX 1/(5 Tcy) 16, 64 Baud 4. This recovery time is mode Initialization only. Recovery time between command writes for Asynchronous Mode is 8 tCY and for Synchronous Mode is 18 tCY. Write Data is allowed only when TXRDY = 1. 5. This recovery time is Status read only. Read Data is allowed only when RXRDY = 1. 6. Status update can have a maximum delay of 28 clock periods from event affecting the status.
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Semiconductor
MSM82C51A-2RS/GS/JS
TIMING CHART
Sytem Clock Input
tf tf tCY
tf CLK
tr
Transmitter Clock and Data
TXC (1 MODE) TXC (16 MODE)
tTPW
tTPD
tDTX TXD
tDTX
Receiver Clock and Data
(RXBAUD Counter starts here) Start bit
RXD RXC (1 Mode) RXC (16 Mode) INT Sampling Pulse
Data bit
Data bit
tRPW
8RXC Periods (16Mode)
tRPD
16 RXC Periods (16 Mode)
3tCY tf
3tCY
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Semiconductor Write Data Cycle (CPU AE USART)
TXRDY WR DATA IN (D. B.) C/D CS
Don't Care
MSM82C51A-2RS/GS/JS
tWW tDW
tTXRDY Clear tWD
Don't Care
Data Stable
tAW tAW
tWA tWA
Read Data Cycle (CPU USART)
RXRDY RD DATA OUT (D. B.) C/D CS
Data Float
tRXRDY Clear tRR tRD
Data Out Active Data Float
tDF
tAR tAR
tRA tRA
Write Control or Output Port Cycle (CPU AE USART)
DTR. RTS WR DATA IN (D. B.) C/D CS Don't Care tAW tAW tWW tDW Data Stable tWA tWA tWC tWD Don't Care
Read Control or Input Port Cycle (CPU USART)
DSR. CTS tCR RD DATA OUT (D. B.) C/D CS tAR tRA Data Float tAR tRR tRD Data Out Active tRA tDF Data Float
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Semiconductor Transmitter Control and Flag Timing (ASYNC Mode)
CTS TXEMPTY TXRDY (STATUS BIT) TXRDY (PIN) C/D Wr TxEn WR TXD DATA CHAR 1 DATA CHAR 2 DATA CHAR 3
MSM82C51A-2RS/GS/JS
tTXEMPTY
tTXRDY
Wr DATA 1 Wr DATA 2 Wr DATA 3 Wr DATA 4
Wr SBRK
DATA CHAR 4
START BIT
0 1 2 3 4 5 6
Note: The wave-form chart is based on the case of 7-bit data length + parity bit + 2 stop bit.
Receiver Control and Flag Timing (ASYNC Mode)
BREAK DETECT FRAMING ERROR (Status Bit) OVERRUN ERROR (Status Bit) RXRDY C/D WR RD RXDATA
Data CHAR 1 Data CHAR 2 Data CHAR 3 Wr RxEn
tRXRDY
DATA CHAR2 Lost Rd Data Wr Error RxEn
Break Data Bit Start Bit Stop Bit Parity Bit
RxEn Err Res
Note: The wave-form chart is based on the case of 7 data bit length + parity bit + 2 stop bit.
Transmitter Control and Flag Timing (SYNC Mode)
CTS TXEMPTY TXRDY (StatusBit) TXRDY (Pin) C/D WR
Marking State Wr Data CHAR1 Wr Data CHAR2 Wr Data CHAR3 Wr Data CHAR4 Wr Commond SBRK Spacing State Wr Data CHAR5 Marking State Data SYNC CHAR5 CHAR ETC 0123 4 012 34 0 1 PAR PAR
TXD
Data Data SYNC SYNC Data Marking CHAR1 CHAR2 CHAR1 SYNC CHAR2 CHAR3 CHAR4 State 0123 4 012 34 0 12 34 01234 012 34 0 123 4 PAR PAR PAR PAR PAR PAR
Note: The wave-form chart is based on the case of 5 data bit length + parity bit and 2 synchronous charactors.
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STOP BIT
Semiconductor Receiver Control and Flag Timing (SYNC Mode)
SYNDET (Pin) (Note 1) SYNDET (SB) OVERRUN ERROR (SB) RXRDY (PIN)
Rd Status Wr Err Res Rd Data CHAR 3 Rd SYNC CHAR 1 Rd Status Wr EHo Data CHAR2 Lost
MSM82C51A-2RS/GS/JS
(Note 2)
tIS
tES
Rd Status
C/D WR RD
Wr EH RxEn
Rd Data CHAR 1
Don't Care RXD RXC
SYNC CHAR 1
SYNC CHAR 2
01234
Data CHAR 1
01234
Data CHAR 2
01234
Data CHAR 3
01234
SYNC CHAR 1
01234
SYNC CHAR 2 Don't Care
01234 xxxxxxx
Data CHAR 1
01234
Data CHAR 2
01x34
ETC PAR
xxxxx x01234
PAR
PAR
PAR PAR CHAR ASSY Begins Exit Hunt Mode Set SYNDET
PAR
PAR
PAR
PAR
CHAR ASSY Begins
PAR
Exit Hunt Mode Set SYNDET (Status bit)
Set SYNDET (Status bit)
Note: 1. Internal Synchronization is based on the case of 5 data bit length + parity bit and 2 synchronous charactor. 2. External Synchronization is based on the case of 5 data bit length + parity bit.
Note: 1. Half-bit processing for the start bit When the MSM82C51A-2 is used in the asynchronous mode, some problems are caused in the processing for the start bit whose length is smaller than the 1-data bit length. (See Fig. 1.)
Start bit Length Smaller than 7-Receiver Clock Length Smaller than 31-Receiver Clock Length 8-Receiver Clock Length 32-Receiver Clock Length 9 to 16-Receiver Clock Length 33 to 64-Receiver Clock Length Mode 16 64 16 64 16 64 Operation The short start bit is ignored. (Normal) The short start bit is ignored. (Normal) Data cannot be received correctly due to a malfunction. Data cannot be received correctly due to a malfunction. The bit is regarded as a start bit. (normal) The bit is regarded as a start bit. (normal)
2. Parity flag after a break signal is received (See Fig. 2.) When the MSM82C51A-2 is used in the asynchrous mode, a parity flag may be set when the next normal data is read after a break signal is received. A parity flag is set when the rising edge of the break signal (end of the break signal) is changed between the final data bit and the parity bit, through a RXRDY signal may not be outputted. If this occurs, the parity flag is left set when the next normal dats is received, and the received data seems to be a parity error.
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Semiconductor Half-bit Processing Timing Chart for the Start bit (Fig. 1)
Normal Operation RXD RXRDY ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
MSM82C51A-2RS/GS/JS
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
The Start bit Is Shorter Than a 1/2 Data bit RXD ST RXRDY ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
The Start bit Is a 1/2 Data bit (A problem of MSM82C51A-2) RXD ST RXRDY A RXRDY signal is outputted during data reception due to a malfunction. The Start bit Is Longer Than a 1/2 Data bit RXD ST RXRDY ST D0 D1 D2 D3 D4 D5 D6 D7 P SP ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
ST: SP: P: D0 - D7:
Start bit Stop bit Parity bit Data bits
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Semiconductor Break Signal Reception Timing and Parity Flag (Fig. 2)
Normal Operation BIT POS. ST D0 D7 P SP ST D0
MSM82C51A-2RS/GS/JS
D7 P SP ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
RXD RXRDY No parity flag is set. and no RXRDY signal is outputted.
Bug Timing
BIT POS.
ST D0
D7 P SP ST D0
D7 P SP ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
RXD RXRDY A parity flag is set, but, no RXRDYsignal is outputted.
Normal Operation BIT POS. ST D0 D7 P SP ST D0
D7 P SP ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
RXD RXRDY A parity flag is set. and a RXRDY signal is outputted.
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Semiconductor
MSM82C51A-2RS/GS/JS
NOTICE ON REPLACING LOW-SPEED DEVICES WITH HIGH-SPEED DEVICES
The conventional low speed devices are replaced by high-speed devices as shown below. When you want to replace your low speed devices with high-speed devices, read the replacement notice given on the next pages.
High-speed device (New) M80C85AH M80C86A-10 M80C88A-10 M82C84A-2 M81C55-5 M82C37B-5 M82C51A-2 M82C53-2 M82C55A-2
Low-speed device (Old) M80C85A/M80C85A-2 M80C86A/M80C86A-2 M80C88A/M80C88A-2 M82C84A/M82C84A-5 M81C55 M82C37A/M82C37A-5 M82C51A M82C53-5 M82C55A-5
Remarks 8bit MPU 16bit MPU 8bit MPU Clock generator RAM.I/O, timer DMA controller USART Timer PPI
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Semiconductor
MSM82C51A-2RS/GS/JS
Differences between MSM82C51A and MSM82C51A-2 1) Manufacturing Process These devices use a 3 m Si-Gate CMOS process technology and have the same chip size. 2) Function These devices have the same logics except for changes in AC characteristics listed in (3-2). 3) Electrical Characteristics 3-1) DC Characteristics
Parameter VOL measurement conditions VOH measurement conditions
Symbol IOL IOH
MSM82C51A +2.0 mA -400 mA
MSM82C51A-2 +2.5 mA -2.5 mA
Although the output voltage characteristics of these devices are identical, but the measurement conditions of the MSM82C51A-2 are more restricted than the MSM82C51A.
3-2) AC Characteristics
Parameter RD Pulse Width RD Rising to Data Difinition RD Rising to Data Float WR Pulse Width Data Setup Time for WR Rising Data Hold Time for WR Rising Master Clock Period Clock Low Time Clock High Time Symbol tRR tRD tRF tWW tDW tWD tCY tf tf MSM82C51A 250 ns minimum 200 ns maximum 100 ns maximum 250 ns minimum 150 ns minimum 20 ns minimum 250 ns minimum 90 ns minimum 120 ns minimum tCY-90 ns maximum MSM82C51A-2 130 ns minimum 100 ns maximum 75 ns minimum 100 ns minimum 100 ns minimum 0 ns minimum 160 ns minimum 50 ns minimum 70 ns minimum tCY-50 ns maximum
As shown above, the MSM82C51A-2 satisfies the characteristics of the MSM82C51A.
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Semiconductor
MSM82C51A-2RS/GS/JS
PACKAGE DIMENSIONS
(Unit : mm)
DIP28-P-600-2.54
Package material Lead frame material Pin treatment Solder plate thickness Package weight (g)
Epoxy resin 42 alloy Solder plating 5 mm or more 4.30 TYP.
Notes for Mounting the Surface Mount Type Package The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which are very susceptible to heat in reflow mounting and humidity absorbed in storage. Therefore, before you perform reflow mounting, contact Oki's responsible sales person for the product name, package name, pin number, package code and desired mounting conditions (reflow method, temperature and times).
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Semiconductor
MSM82C51A-2RS/GS/JS
(Unit : mm)
QFJ28-P-S450-1.27
Spherical surface
Package material Lead frame material Pin treatment Solder plate thickness Package weight (g)
Epoxy resin Cu alloy Solder plating 5 mm or more 1.00 TYP.
Notes for Mounting the Surface Mount Type Package The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which are very susceptible to heat in reflow mounting and humidity absorbed in storage. Therefore, before you perform reflow mounting, contact Oki's responsible sales person for the product name, package name, pin number, package code and desired mounting conditions (reflow method, temperature and times).
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Semiconductor
MSM82C51A-2RS/GS/JS
(Unit : mm)
SSOP32-P-430-1.00-K
Mirror finish
Package material Lead frame material Pin treatment Solder plate thickness Package weight (g)
Epoxy resin 42 alloy Solder plating 5 mm or more 0.60 TYP.
Notes for Mounting the Surface Mount Type Package The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which are very susceptible to heat in reflow mounting and humidity absorbed in storage. Therefore, before you perform reflow mounting, contact Oki's responsible sales person for the product name, package name, pin number, package code and desired mounting conditions (reflow method, temperature and times).
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Semiconductor
4) Notices on use
MSM82C51A-2RS/GS/JS
Note the following when replacing devices as the ASYNC pin is differently treated between the MSM82C84A and the MSM82C84A-5/MSM82C84A-2: Case 1: When only a pullup resistor is externally connected to. The MSM82C84A can be replaced by the MSM82C84A-2. Case 2: When only pulldown resistor is externally connected to. When the pulldown resistor is 8 kiloohms or less, the MSM82C84A can be replaced by the MSM82C84A-2. When the pulldown resistor is greater than 8 kiloohms, use a pulldown resistor of 8 kiloohms or less. Case 3: When an output of the other IC device is connected to the device. The MSM82C84A can be replaced by the MSM82C84A-2 when the IOL pin of the device to drive the ASYNC pin of the MSM82C84A-2 has an allowance of 100 mA or more.
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