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| AT90S2323 Features * * * * * * * * * * * * * * * * * * * Utilizes the AVR (R) Enhanced RISC Architecture AVR - High Performance and Low Power RISC Architecture 120 Powerful Instructions - Most Single Clock Cycle Execution 2K bytes of In-System Reprogrammable Downloadable Flash - SPI Serial Interface for Program Downloading - Endurance: 1,000 Write/Erase Cycles 128 bytes EEPROM - Endurance: 100,000 Write/Erase Cycles 128 bytes Internal RAM 32 x 8 General Purpose Working Registers 5 Programmable I/O Lines VCC: 2.7 - 6.0V Power-On Reset Circuit Fully Static Operation, 0 - 8 MHz (4.0 - 6.0V) Instruction Cycle Time: 125ns @ 8 MHz One 8-Bit Timer/Counter with Separate Prescaler External and Internal Interrupt Sources Programmable Watchdog Timer with On-Chip Oscillator Low Power Idle and Power Down Modes Programming lock for Flash Program and EEPROM Data Security Selectable On-Chip RC Oscillator 8-Pin Device 8-Bit Microcontroller with 2K bytes Downloadable Flash AT90S2323 Preliminary AT90S2323 Description The AT90S2323 is a low-power CMOS 8-bit microcontroller based on the AVR (R) enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the AT90S2323 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. The AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers. (continued) Pin Configuration PDIP/SOIC RESET (X TAL1) PB3 (X TAL2) PB4 GND 1 2 3 4 8 7 6 5 VCC PB2 (SCK/T0) PB1 (MISO/INT0) PB0 (MOSI) 0970A-A-10/97 1 Block Diagram VCC 8-BIT DATA BUS INTERNAL OSCILLATOR GND PROGRAM COUNTER STACK POINTER WATCHDOG TIMER TIMING AND CONTROL RESET PROGRAM FLASH SRAM MCU CONTROL REGISTER INSTRUCTION REGISTER GENERAL PURPOSE REGISTERS X Y Z TIMER/ COUNTER INSTRUCTION DECODER INTERRUPT UNIT CONTROL LINES ALU EEPROM STATUS REGISTER PROGRAMMING LOGIC SPI OSCILLATOR DATA REGISTER PORTB DATA DIR. REG. PORTB PORTB DRIVERS PB0 - PB4 Figure 1. The AT90S2323 Block Diagram 2 AT90S2323 AT90S2323 Description (Continued) The AT90S2323 provides the following features: 2K bytes of Downloadable Flash, 128 bytes EEPROM, 128 bytes SRAM, 5 general purpose I/O lines, 32 general purpose working registers, an 8-bit timer/counter, internal and external interrupts, programmable Watchdog Timer with internal oscillator, an SPI serial port for Flash Memory downloading and two software selectable power saving modes. The Idle Mode stops the CPU while allowing the SRAM, timer/counters, SPI port and interrupt system to continue functioning. The power down mode saves the register contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset. The device is manufactured using Atmel's high density non-volatile memory technology. The on-chip Downloadable Flash allows the program memory to be reprogrammed in-system through an SPI serial interface. By combining an enhanced RISC 8-bit CPU with Downloadable Flash on a monolithic chip, the Atmel AT90S2323 is a powerful microcontroller that provides a highly flexible and cost effective solution to many embedded control applications. The AT90S2323 AVR is supported with a full suite of program and system development tools including: C compilers, macro assemblers, program debugger/simulators, in-circuit emulators, and evaluation kits. Pin Descriptions VCC Supply voltage pin. GND Ground pin. Port B (PB4..PB0) Port B is an 5-bit bi-directional I/O port. Port pins can provide internal pullups (selected for each bit). When the device is used with an external oscillator, Port B is a 3-bit I/O Port. RESET Reset input. A low on this pin for two machine cycles while the oscillator is running resets the device. XTAL1 Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2 Output from the inverting oscillator amplifier Crystal Oscillator XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can be configured for use as an onchip oscillator, as shown in Figure 2. Either a quartz crystal or a ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 3. 3 Figure 2. Oscillator Connections Figure 3. External Clock Drive Configuration On-Chip RC Oscillator An on-chip RC oscillator running at a fixed frequency of 1 MHz can be selected as the MCU clock source. If enabled, the AT90S2323 can operate with no external components. A fuse bit - RCEN in the Flash memory selects the on-chip RC oscillator as the clock source when programmed (`0'). The AT90S2323 is shipped with this bit programmed. 4 AT90S2323 AT90S2323 AT90S2323 AVR Enhanced RISC Microcontroller CPU The AT90S2323 AVR RISC microcontroller is upward compatible with the AVR Enhanced RISC Architecture. The programs written for the AT90S2323 MCU are fully compatible with the range of AVR 8-bit MCUs (AT90Sxxxx) with respect to source code and clock cycles for execution. Architectural Overview The fast-access register file concept contains 32 x 8-bit general purpose working registers with a single clock cycle access time. This means that during one single clock cycle, one ALU (Arithmetic Logic Unit) operation is executed. Two operands are output from the register file, the operation is executed, and the result is stored back in the register file - in one clock cycle. Six of the 32 registers can be used as three 16-bits indirect address register pointers for Data Space addressing - enabling efficient address calculations. One of the three address pointers is also used as the address pointer for the constant table look up function. These added function registers are the 16-bit X-register, Y-register and Z-register. The ALU supports arithmetic and logic functions between registers or between a constant and a register. Single register operations are also executed in the ALU. Figure 4 shows the AT90S2323 AVR Enhanced RISC microcontroller architecture. In addition to the register operation, the conventional memory addressing modes can be used on the register file as well. This is enabled by the fact that the register file is assigned the 32 lowermost Data Space addresses ($00 - $1F), allowing them to be accessed as though they were ordinary memory locations. The I/O memory space contains 64 addresses for CPU peripheral functions as Control Registers, Timer/Counters, A/Dconverters, and other I/O functions. The I/O memory can be accessed directly, or as the Data Space locations following those of the register file, $20 - $5F. The AVR has Harvard architecture - with separate memories and buses for program and data. The program memory is accessed with a single level pipelining. While one instruction is being executed, the next instruction is pre-fetched from the program memory. This concept enables instructions to be executed in every clock cycle. The program memory is in-system downloadable Flash memory. With the relative jump and call instructions, the whole 1K address space is directly accessed. Most AVR instructions have a single 16-bit word format. Every program memory address contains a 16- or 32-bit instruction. During interrupts and subroutine calls, the return address program counter (PC) is stored on the stack. The stack is effectively allocated in the general data SRAM, and consequently the stack size is only limited by the total SRAM size and the usage of the SRAM. All user programs must initialize the SP in the reset routine (before subroutines or interrupts are executed). The 8-bit stack pointer SP is read/write accessible in the I/O space. The 128 bytes data SRAM + register file and I/O registers can be easily accessed through the five different addressing modes supported in the AVR architecture. The memory spaces in the AVR architecture are all linear and regular memory maps. 5 AVR AT90S2323 Architecture Data Bus 8-bit 1K x 16 Program FLASH Program Counter Status and Test Control Registrers Interrupt Unit SPI Unit 8-bit Timer/Counter Instruction Register 32 x 8 General Purpose Registrers Indirect Addressing Instruction Decoder Direct Addressing ALU Watchdog Timer Control Lines 128 x 8 Data SRAM 128 x 8 EEPROM Figure 4. The AT90S2323 AVR Enhanced RISC Architecture Figure 5. Memory Maps 6 AT90S2323 AT90S2323 A flexible interrupt module has its control registers in the I/O space with an additional global interrupt enable bit in the status register. All the different interrupts have a separate interrupt vector in the interrupt vector table at the beginning of the program memory. The different interrupts have priority in accordance with their interrupt vector position. The lower the interrupt address vector the higher the priority. The General Purpose Register File Figure 6 shows the structure of the 32 general purpose registers in the CPU. 7 R0 R1 R2 ... R13 General Purpose Working Registers R14 R15 R16 R17 ... R26 R27 R28 R29 R30 R31 0 Addr. $00 $01 $02 $0D $0E $0F $10 $11 $1A $1B $1C $1D $1E $1F X-register low byte X-register high byte Y-register low byte Y-register high byte Z-register low byte Z-register high byte Figure 6. AVR CPU General Purpose Working Registers All the register operating instructions in the instruction set have direct and single cycle access to all registers. The only exception is the five constant arithmetic and logic instructions SBCI, SUBI, CPI, ANDI, ORI between a constant and a register and the LDI instruction for load immediate constant data. These instructions apply to the second half of the registers in the register file - R16..R31. The general SBC, SUB, CP, AND, OR and all other operations between two registers or on a single register apply to the entire register file. As shown in Figure 6, each register is also assigned a data memory address, mapping them directly into the first 32 locations of the user Data Space. Although the register file is not physically implemented as SRAM locations, this memory organization provides great flexibility in access of the registers, as the X, Y and Z registers can be set to index any register in the file. 7 THE X-REGISTER, Y-REGISTER, AND Z-REGISTER The registers R26..R31 have some added functions to their general purpose usage. These registers are the address pointers for indirect addressing of the Data Space. The three indirect address registers X, Y and Z are defined as: 15 X - register 7 R27 ($1B) 0 7 R26 ($1A) 0 0 15 Y - register 7 R29 ($1D) 0 7 R28 ($1C) 0 0 15 Z - register 7 R31 ($1F) 0 7 R30 ($1E) 0 0 Figure 7. The X, Y, and Z Registers In the different addressing modes these address registers have functions as fixed displacement, automatic increment and decrement (see the descriptions for the different instructions). The ALU - Arithmetic Logic Unit The high-performance AVR ALU operates in direct connection with all the 32 general purpose working registers. Within a single clock cycle, ALU operations between registers in the register file are executed. The ALU operations are divided into three main categories - arithmetic, logic and bit-functions. Some microcontrollers in the AVR product family feature a hardware multiplier in the arithmetic part of the ALU. The Downloadable Flash Program Memory The AT90S2323 contains 2K bytes on-chip downloadable Flash memory for program storage. Since all instructions are 16or 32-bit words, the Flash is organized as 1K x 16. The Flash memory has an endurance of at least 1000 write/erase cycles. The AT90S2323 Program Counter PC is 10 bits wide, hence addressing the 1024 program memory addresses. See Page 3-32 for a detailed description on Flash data downloading. Constant tables must be allocated within the address 0-2K (see the LPM - Load Program Memory instruction description). See Page 3-10 for the different addressing modes. 8 AT90S2323 AT90S2323 The EEPROM Data Memory The AT90S2323 contains 128 bytes of EEPROM data memory. It is organized as a separate data space, in which single bytes can be read and written. The EEPROM has an endurance of at least 100,000 write/erase cycles. The access between the EEPROM and the CPU is described on Page 3-40 specifying the EEPROM address register, the EEPROM data register, and the EEPROM control register. For the SPI data downloading, see Page 3-35 for a detailed description. The SRAM Data Memory The following figure shows how the AT90S2323 Data Memory is organized: Register File R0 R1 R2 Data Address Space $00 $01 $02 ... R29 R30 R31 I/O Registers $00 $01 $02 ... $1D $1E $1F $20 $21 $22 ... $3D $3E $3F ... $5D $5E $5F Internal SRAM $60 $61 $62 ... $DD $DE $DF Figure 8. SRAM Organization The 224 Data Memory locations address the Register file, I/O Memory and the data SRAM. The first 96 locations address the Register File + I/O Memory, and the next 128 locations address the data SRAM. The five different addressing modes for the data memory cover: Direct, Indirect with Displacement, Indirect, Indirect with Pre-Decrement and Indirect with Post-Increment. In the register file, registers R26 to R31 feature the indirect addressing pointer registers. The Direct addressing reaches the entire data address space. The Indirect with Displacement mode features 63 address locations reach from the base address given by the Y and Z register. When using register indirect addressing modes with automatic pre-decrement and post-increment, the address registers X, Y and Z are used and decremented and incremented. 9 The 32 general purpose working registers, 64 I/O registers and the 128 bytes of data SRAM in the AT90S2323 are all directly accessible through all these addressing modes. The Program and Data Addressing Modes The AT90S2323 AVR Enhanced RISC Microcontroller supports powerful and efficient addressing modes for access to the program memory (Flash) and data memory. This section describes the different addressing modes supported by the AVR architecture. In the figures, OP means the operation code part of the instruction word. To simplify, not all figures show the exact location of the addressing bits. REGISTER DIRECT, SINGLE REGISTER RD Figure 9. Direct Single Register Addressing The operand is contained in register d (Rd). REGISTER DIRECT, TWO REGISTERS RD AND RR Figure 10. Direct Register Addressing, Two Registers Operands are contained in register r (Rr) and d (Rd). The result is stored in register d (Rd). 10 AT90S2323 AT90S2323 I/O DIRECT Figure 11. I/O Direct Addressing Operand address is contained in 6 bits of the instruction word. n is the destination or source register address. DATA DIRECT Figure 12. Direct Data Addressing A 16-bit Data Address is contained in the 16 LSBs of a two-word instruction. Rd/Rr specify the destination or source register. DATA INDIRECT WITH DISPLACEMENT Figure 13. Data Indirect with Displacement Operand address is the result of the Y or Z-register contents added to the address contained in 6 bits of the instruction word. 11 DATA INDIRECT Figure 14. Data Indirect Addressing Operand address is the contents of the X, Y or the Z-register. DATA INDIRECT WITH PRE-DECREMENT Figure 15. Data Indirect Addressing With Pre-Decrement The X, Y or the Z-register is decremented before the operation. Operand address is the decremented contents of the X, Y or the Z-register. DATA INDIRECT WITH POST-INCREMENT Figure 16. Data Indirect Addressing With Post-Increment The X, Y or the Z-register is incremented after the operation. Operand address is the content of the X, Y or the Z-register prior to incrementing. 12 AT90S2323 AT90S2323 CONSTANT ADDRESSING USING THE LPM INSTRUCTION Figure 17. Code Memory Constant Addressing Constant byte address is specified by the Z-register contents. The 15 MSBs select word address (0 - 1K), and LSB selects low byte if cleared (LSB = 0) or high byte if set (LSB = 1). INDIRECT PROGRAM ADDRESSING, IJMP AND ICALL Figure 18. Indirect Program Memory Addressing Program execution continues at address contained by the Z-register (i.e., the PC is loaded with the content of the Z-register). RELATIVE PROGRAM ADDRESSING, RJMP AND RCALL Figure 19. Relative Program Memory Addressing Program execution continues at address PC + k. The relative address k is in the range from -2K to +(2K - 1). 13 Memory Access and Instruction Execution Timing This section describes the general access timing concepts for instruction execution and internal memory access. The AVR CPU is driven by the System Clock O, directly generated from the external clock crystal for the chip. No internal clock division is used. Figure 20 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast-access register file concept. This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost, functions per clocks, and functions per power-unit. T1 T2 T3 T4 System Clock O 1st Instruction Fetch 1st Instruction Execute 2nd Instruction Fetch 2nd Instruction Execute 3rd Instruction Fetch 3rd Instruction Execute 4th Instruction Fetch Figure 20. The Parallel Instruction Fetches and Instruction Executions Figure 21 shows the internal timing concept for the register file. In a single clock cycle an ALU operation using two register operands is executed, and the result is stored back to the destination register. T1 T2 T3 T4 System Clock O Total Execution Time Register Operands Fetch ALU Operation Execute Result Write Back Figure 21. Single Cycle ALU Operation 14 AT90S2323 AT90S2323 The internal data SRAM access is performed in two System Clock cycles as described in Figure 22. T1 T2 T3 T4 System Clock O Address Data WR Data RD Prev. Address Address Figure 22. On-Chip Data SRAM Access Cycles Read Write 15 I/O Memory The I/O space definition of the AT90S2323 is shown in the following table: Table 1. AT90S2323 I/O Space Address Hex $3F ($5F) $3D ($5D) $3B ($5B) $3A ($5A) $39 ($59) $38 ($58) $35 ($55) $34 ($54) $33 ($53) $32 ($52) $21 ($41) $1E ($3E) $1D ($3D) $1C ($3C) $18 ($38) $17 ($37) $16 ($36) Name SREG SPL GIMSK GIFR TIMSK TIFR MCUCR MCUSR TCCR0 TCNT0 WDTCR EEAR EEDR EECR PORTB DDRB PINB Function Status REGister Stack Pointer Low General Interrupt MaSK register General Interrupt Flag Register Timer/Counter Interrupt MaSK register Timer/Counter Interrupt Flag register MCU Control Register MCU Status Register Timer/Counter 0 Control Register Timer/Counter 0 (8-bit) Watchdog Timer Control Register EEPROM Address Register EEPROM Data Register EEPROM Control Register Data Register, Port B Data Direction Register, Port B Input Pins, Port B Note: Reserved and unused locations are not shown in the table. All the different AT90S2323 I/O and peripherals are placed in the I/O space. The different I/O locations are accessed by the IN and OUT instructions transferring data between the 32 general purpose working registers and the I/O space. I/O registers within the address range $00 - $1F are directly bit-accessible using the SBI and CBI instructions. In these registers, the value of single bits can be checked by using the SBIS and SBIC instructions. Refer to the instruction set chapter for more details. When using the I/O specific commands, IN, OUT,SBIS and SBIC, the I/O addresses $00 - $3F must be used. When addressing I/O registers as SRAM, $20 must be added to this address. All I/O register addresses throughout this document are shown with the SRAM address in parentheses. The different I/O and peripherals control registers are explained in the following sections. THE STATUS REGISTER - SREG The AVR status register - SREG - at I/O space location $3F ($5F) is defined as: Bit $3F ($5F) Read/Write Initial value 7 I R/W 0 6 T R/W 0 5 H R/W 0 4 S R/W 0 3 V R/W 0 2 N R/W 0 1 Z R/W 0 0 C R/W 0 SREG 16 AT90S2323 AT90S2323 Bit 7 - I : Global Interrupt Enable: The global interrupt enable bit must be set (one) for the interrupts to be enabled. The individual interrupt enable control is then performed in the interrupt mask registers - GIMSK and TIMSK. If the global interrupt enable register is cleared (zero), none of the interrupts are enabled independent of the GIMSK and TIMSK values. The I-bit is cleared by hardware after an interrupt has occurred, and is set by the RETI instruction to enable subsequent interrupts. Bit 6 - T : Bit Copy Storage: The bit copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T bit as source and destination for the operated bit. A bit from a register in the register file can be copied into T by the BST instruction, and a bit in T can be copied into a bit in a register in the register file by the BLD instruction. Bit 5 - H : Half Carry Flag: The half carry flag H indicates a half carry in some arithmetic operations. See the Instruction Set Description for detailed information. Bit 4 - S : Sign Bit, S = N V : The S-bit is always an exclusive or between the negative flag N and the two's complement overflow flag V. See the Instruction Set Description for detailed information. Bit 3 - V : Two's Complement Overflow Flag: The two's complement overflow flag V supports two's complement arithmetics. See the Instruction Set Description for detailed information. Bit 2 - N : Negative Flag: The negative flag N indicates a negative result after the different arithmetic and logic operations. See the Instruction Set Description for detailed information. Bit 1 - Z : Zero Flag: The zero flag Z indicates a zero result after the different arithmetic and logic operations. See the Instruction Set Description for detailed information. Bit 0 - C : Carry Flag: The carry flag C indicates a carry in an arithmetic or logic operation. See the Instruction Set Description for detailed information. THE STACK POINTER - SPL An 8-bit register at I/O address $3D ($5D) forms the stack pointer of the AT90S2323. 8 bits are used to address the 128 bytes of SRAM in locations $60 - $DF. Bit $3D ($5D) Read/Write Initial value 7 SP7 R/W 0 6 SP6 R/W 0 5 SP5 R/W 0 4 SP4 R/W 0 3 SP3 R/W 0 2 SP2 R/W 0 1 SP1 R/W 0 0 SP0 R/W 0 SPL The Stack Pointer points to the data SRAM stack area where the Subroutine and Interrupt Stacks are located. This Stack space in the data SRAM must be defined by the program before any subroutine calls are executed or interrupts are enabled. The Stack Pointer is decremented by one when data is pushed onto the Stack with the PUSH instruction, and it is decremented by two when data is pushed onto the Stack with subroutine CALL and interrupt. The Stack Pointer is incremented by one when data is popped from the Stack with the POP instruction, and it is incremented by two when data is popped from the Stack with return from subroutine RET or return from interrupt IRET. Reset and Interrupt Handling The AT90S2323 provides 2 interrupt sources. These interrupts and the separate reset vector, each have a separate program vector in the program memory space. Both interrupts are assigned individual enable bits which must be set (one) together with the I-bit in the status register in order to enable the interrupt. The lowest addresses in the program memory space are automatically defined as the Reset and Interrupt vectors. The complete list of vectors is shown in Table 2. The list also determines the priority levels of the interrupts. The lower the 17 address the higher is the priority level. RESET has the highest priority, and next is INT0 - the External Interrupt Request 0, etc. Table 2. Reset and Interrupt Vectors Vector No. 1 2 3 Program Address $000 $001 $002 Source RESET INT0 TIMER0, OVF0 Interrupt Definition Hardware Pin and Watchdog Reset External Interrupt Request 0 Timer/Counter0 Overflow The most typical and general program setup for the Reset and Interrupt Vector Addresses are: Address $000 $001 $002 ; $003 ... MAIN: ... RESET SOURCES The AT90S2323 provides three sources of reset: * Power-On Reset. The MCU is reset when a supply voltage is applied to the VCC and GND pins. * External Reset. The MCU is reset when a low level is present on the RESET pin for more than two XTAL cycles * Watchdog Reset. The MCU is reset when the Watchdog timer period expires and the Watchdog is enabled. During reset, all I/O registers are then set to their initial values, and the program starts execution from address $000. The instruction placed in address $000 must be an RJMP - relative jump - instruction to the reset handling routine. If the program never enables an interrupt source, the interrupt vectors are not used, and regular program code can be placed at these locations. The circuit diagram in Figure 23 shows the reset logic. Table 3 defines the timing and electrical parameters of the reset circuitry. VCC 100 - 500K RESET Reset Circuit S Q Power-On Reset Circuit POR Watchdog Timer COUNTER RESET RCEN On-Chip RC-Oscillator 14-Stage Ripple Counter Q0 Q3 Q13 R Q INTERNAL RESET Figure 23. Reset Logic 18 AT90S2323 AT90S2323 Table 3. Reset Characteristics (VCC = 5.0V) Symbol VPOT VRST tTOUT tTOUT Parameter Power-On Reset Threshold Voltage RESET Pin Threshold Voltage Reset Delay Time-Out Period RCEN Unprogrammed Reset Delay Time-Out Period RCEN Programmed 11 11 Min 1.8 Typ 2 0.6 VCC 16 16 21 21 Max 2.2 Units V V ms s POWER-ON RESET A Power-On Reset (POR) circuit ensures that the device is not started until VCC has reached a safe level. As shown in Figure 23, an internal timer is clocked from the Watchdog timer. This timer prevents the MCU from starting until after a certain period after VCC has reached the Power-On Threshold voltage - VPOT. See Figure 24 and Figure 25. The total reset period is the Power-On Reset period - tPOR + the Delay Time-out period - tTOUT . When the chip is clocked from the internal RCoscillator, it starts execution after 16 clock cycles. If the build-in start-up delay is sufficient, RESET can be connected to VCC directly or via an external pull-up resistor. By holding the RESET pin low for a period after VCC has been applied, the Power-On Reset period can be extended. Refer to Figure 26 for a timing example on this. VCC VPOT RESET VRST TIME-OUT tTOUT INTERNAL RESET Figure 24. MCU Start-Up, RESET Tied to VCC or Unconnected. Rapidly Rising VCC 19 VCC VPOT RESET VRST TIME-OUT tTOUT INTERNAL RESET Figure 25. MCU Start-Up, RESET Tied to VCC or Unconnected. Slowly Rising VCC VCC VPOT RESET VRST TIME-OUT tTOUT INTERNAL RESET Figure 26. MCU Start-Up, RESET Controlled Externally 20 AT90S2323 AT90S2323 EXTERNAL RESET An external reset is generated by a low level on the RESET pin. The RESET pin must be held low for at least two crystal clock cycles. When tha applied voltage reaches the Reset Threshold Voltage - V RST on its positive edge, the delay timer starts the MCU after the Time-out period tTOUT has expired. Figure 27. External Reset During Operation WATCHDOG RESET When the Watchdog times out, it will generate a short reset pulse of 1 XTAL cycle duration. On the falling edge of this pulse, the delay timer starts counting the Time-out period tTOUT . Refer to Page 3-28 for details on operation of the Watchdog. Figure 28. Watchdog Reset During Operation THE MCU STATUS REGISTER - MCUSR The MCU Status Register provides information on which reset source caused an MCU reset.: Bit $34 ($54) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 R 0 3 R 0 2 R 0 1 EXTRF R/W 0 PORF R/W MCUCR See bit description Bit 7..2 - Res : Reserved Bits: These bits are reserved bits in the AT90S2323 and always read as zero. Bit 1 - EXTRF : External Reset Flag: After a power-on reset, this bit is undefined (X). It will be set by an external reset. A watchdog reset will leave this bit unchanged. To summarize, the following table shows the value of these two bits after the three modes of reset. 21 Bit 0 - PORF : Power On Reset Flag: This bit is set by a power-on reset. A watchdog reset or an external reset will leave this bit unchanged. Table 4: PORF and EXTRF Values after Reset Reset Source Power-On or BrownOut Reset External Reset Watchdog Reset PORF 1 unchanged unchanged EXTRF undefined 1 unchanged To make use of these bits to identify a reset condition, the user software should clear both the PORF and EXTRF bits as early as possible in the program. Checking the PORF and EXTRF values is done before the bits are cleared. If the bit is cleared before an external or watchdog reset occurs, the source of reset can be found by using the following truth table: Table 5: Reset Source Identification PORF 0 0 1 1 EXTRF 0 1 0 1 Reset Source Watchdog Reset External Reset Power-On Reset Power-On Reset INTERRUPT HANDLING The AT90S2323 has two 8-bit Interrupt Mask control registers; GIMSK - General Interrupt Mask register and TIMSK Timer/Counter Interrupt Mask register. When an interrupt occurs, the Global Interrupt Enable I-bit is cleared (zero) and all interrupts are disabled. The user software can set (one) the I-bit to enable interrupts. The I-bit is set (one) when a Return from Interrupt instruction - RETI - is executed. For Interrupts triggered by events that can remain static (e.g. the Output Compare register1 matching the value of Timer/ Counter1) the interrupt flag is set when the event occurs. If the interrupt flag is cleared and the interrupt condition persists, the flag will not be set until the event occurs the next time. When the Program Counter is vectored to the actual interrupt vector in order to execute the interrupt handling routine, hardware clears the corresponding flag that generated the interrupt. Some of the interrupt flags can also be cleared by writing a logic one to the flag bit position(s) to be cleared. THE GENERAL INTERRUPT MASK REGISTER - GIMSK Bit $3B ($5B) Read/Write Initial value 7 R 0 6 INT0 R/W 0 5 R 0 4 R 0 3 R 0 2 R 0 1 R 0 0 R 0 GIMSK Bit 7 - Res : Reserved Bit This bit is a reserved bit in the AT90S2323 and always reads as zero Bit 6 - INT0 : External Interrupt Request 0 Enable: When the INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is activated. The Interrupt Sense Control0 bits 1/0 (ISC01 and ISC00) in the MCU general Control Register (MCUCR) defines whether the external interrupt is activated on rising or falling edge of the INT0 pin or level sensed. Activity on the pin will cause an interrupt request even if INT0 is configured as an output. The corresponding interrupt of External Interrupt Request 0 is executed from program memory address $001. See also "External Interrupts." 22 AT90S2323 AT90S2323 Bits 5..0 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and always read as zero. THE GENERAL INTERRUPT FLAG REGISTER - GIFR Bit $3A ($5A) Read/Write Initial value 7 R 0 6 INTF0 R/W 0 5 R 0 4 R 0 3 R 0 2 R 0 1 R 0 0 R 0 GIFR Bit 7 - Res : Reserved Bit This bit is a reserved bit in the AT90S2323 and always reads as zero Bit 6 - INTF0 : External Interrupt Flag0: When an event on the INT0 pin triggers an interrupt request, INTF0 becomes set (one). If the I-bit in SREG and the INT0 bit in GIMSK are set (one), the MCU will jump to the interrupt vector at address $001. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. Bits 5..0 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and always read as zero. THE TIMER/COUNTER INTERRUPT MASK REGISTER - TIMSK Bit $39 ($59) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 R 0 3 R 0 2 R 0 1 TOIE0 R/W 0 0 R 0 TIMSK Bit 7..2 - Res :Reserved bits: These bits are reserved bits in the AT90S2323 and always read zero. Bit 1 - TOIE0 : Timer/Counter0 Overflow Interrupt Enable: When the TOIE0 bit is set (one) and the I-bit in the Status Register is set (one), the Timer/Counter0 Overflow interrupt is enabled. The corresponding interrupt (at vector $002) is executed if an overflow in Timer/Counter0 occurs. The Overflow Flag (Timer0) is set (one) in the Timer/Counter Interrupt Flag Register - TIFR. Bit 0 - Res : Reserved bit: This bit is a reserved bit in the AT90S2323 and always reads as zero. THE TIMER/COUNTER INTERRUPT FLAG REGISTER - TIFR Bit $38 ($58) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 R 0 3 R 0 2 R 0 1 TOV0 R/W 0 0 R 0 TIFR Bits 7..2 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and always read zero. Bit 1 - TOV0 : Timer/Counter0 Overflow Flag: The bit TOV0 is set (one) when an overflow occurs in Timer/Counter0. TOV0 is cleared by hardware when executing the corresponding interrupt handling vector. Alternatively, TOV0 is cleared by writing a logical one to the flag. When the SREG I-bit, and TOIE0 (Timer/Counter0 Overflow Interrupt Enable), and TOV0 are set (one), the Timer/Counter0 Overflow interrupt is executed. Bit 0 - Res : Reserved bit: This bit is a reserved bit in the AT90S2323 and always reads zero. 23 EXTERNAL INTERRUPTS The external interrupt is triggered by the INT0 pin. Observe that, if enabled, the interrupts will trigger even if the INT0 pin is configured as an output. This feature provides a way of generating a software interrupt. The external interrupt can be triggered by a falling or rising edge or a low level. This is set up as indicated in the specification for the MCU Control Register - MCUCR. When the external interrupt is enabled and is configured as level triggered, the interrupt will trigger as long as the pin is held low. The external interrupts are set up as described in the specification for the MCU Control Register - MCUCR. INTERRUPT RESPONSE TIME The interrupt execution response for all the enabled AVR interrupts is 4 clock cycles minimum. After the 4 clock cycles the program vector address for the actual interrupt handling routine is executed. During this 4 clock cycle period, the Program Counter (2 bytes) is pushed onto the Stack, and the Stack Pointer is decremented by 2. The vector is a relative jump to the interrupt routine, and this jump takes 2 clock cycles. If an interrupt occurs during execution of a multi-cycle instruction, this instruction is completed before the interrupt is served. A return from an interrupt handling routine takes 4 clock cycles. During these 4 clock cycles, the Program Counter (2 bytes) is popped back from the Stack, and the Stack Pointer is incremented by 2. When AVR exits from an interrupt, it will always return to the main program and execute one more instruction before any pending interrupt is served. Note that the Status Register - SREG - is not handled by the AVR hardware, neither for interrupts nor for subroutines. For the routines requiring a storage of the SREG, this must be performed by user software. THE MCU CONTROL REGISTER - MCUCR The MCU Control Register contains control bits for general MCU functions. Bit $35 ($55) Read/Write Initial value 7 R 0 6 R 0 5 SE R/W 0 4 SM R/W 0 3 R 0 2 R 0 1 ISC01 R/W 0 0 ISC00 R/W 0 MCUCR Bits 7, 6 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and always read as zero. Bit 5 - SE : Sleep Enable: The SE bit must be set (one) to make the MCU enter the sleep mode when the SLEEP instruction is executed. To avoid the MCU entering the sleep mode unless it is the programmers purpose, it is recommended to set the Sleep Enable SE bit just before the execution of the SLEEP instruction. Bit 4 - SM : Sleep Mode: This bit selects between the two available sleep modes. When SM is cleared (zero), Idle Mode is selected as Sleep Mode. When SM is set (one), Power Down mode is selected as sleep mode. For details, refer to the paragraph "Sleep Modes" below. Bits 3, 2 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and always read as zero. Bits 1, 0 - ISC01, ISC00 : Interrupt Sense Control 0 bit 1 and bit 0: The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corresponding interrupt mask is set. The level and edges on the external INT0 pin that activate the interrupt are defined in the following table: 24 AT90S2323 AT90S2323 Table 6.. Interrupt 0 Sense Control ISC01 0 0 1 1 ISC00 0 1 0 1 Description The low level of INT0 generates an interrupt request. Reserved The falling edge of INT0 generates an interrupt request. The rising edge of INT0 generates an interrupt request. Notes: When changing the ISC10/ISC00 bits, INT0 must be disabled by clearing its Interrupt Enable bit in the GIMSK Register. Otherwise an interrupt can occur when the bits are changed. Sleep Modes To enter the sleep modes, the SE bit in MCUCR must be set (one) and a SLEEP instruction must be executed. If an enabled interrupt occurs while the MCU is in a sleep mode, the MCU awakes, executes the interrupt routine, and resumes execution from the instruction following SLEEP. The contents of the register file, SRAM and I/O memory are unaltered. If a reset occurs during sleep mode, the MCU wakes up and executes from the Reset vector. Note that if a level triggered interrupt is used for wake-up from power down, the low level must be held for a time longer than the oscillator start-up time of 16 ms. Otherwise, the interrupt flag may return to zero before the MCU starts executing. IDLE MODE When the SM bit is cleared (zero), the SLEEP instruction forces the MCU into the Idle Mode stopping the CPU but allowing Timer/Counters, Watchdog and the interrupt system to continue operating. This enables the MCU to wake up from external triggered interrupts as well as internal ones like Timer Overflow interrupt and watchdog reset. If wakeup from the Analog Comparator interrupt is not required, the analog comparator can be powered down by setting the ACD-bit in the Analog Comparator Control and Status register - ACSR. This will reduce power consumption during Idle Mode. POWER DOWN MODE When the SM bit is set (one), the SLEEP instruction forces the MCU into the Power Down Mode. In this mode, the external oscillator is stopped. The user can select whether the watchdog shall be enabled during power-down mode. If the watchdog is enabled, it will wake up the MCU when the Watchdog Time-out period expires. If the watchdog is disabled, only an external reset or an external level triggered interrupt can wake up the MCU. 25 Timer / Counter The AT90S2323 provides one general purpose 8- bit Timer/Counter - Timer/Counter0. The Timer/Counter has prescaling selection from the 10-bit prescaling timer. The Timer/Counter can either be used as a timer with an internal clock timebase or as a counter with an external pin connection that triggers the counting. The Timer/Counter Prescaler Figure 29 shows the Timer/Counter prescaler. CK 10-BIT T/C PRESCALER CK/64 CK/8 CK/256 EXT 0 CS00 CS01 CS02 TIMER/COUNTER0 CLOCK SOURCE Figure 29. Timer/Counter0 Prescaler The four different prescaled selections are: CK/8, CK/64, CK/256 and CK/1024 where CK is the oscillator clock. CK, external source and stop, can also be selected as clock sources. The 8-Bit Timer/Counter0 Figure 30 shows the block diagram for Timer/Counter0. The 8-bit Timer/Counter0 can select clock source from CK, prescaled CK, or an external pin. In addition, it can be stopped as described in the specification for the Timer/Counter0 Control Register - TCCR0. The overflow status flag is found in the Timer/Counter Interrupt Flag Register - TIFR. Control signals are found in the Timer/Counter0 Control Register - TCCR0. The interrupt enable/disable settings for Timer/Counter0 are found in the Timer/Counter Interrupt Mask Register - TIMSK. When Timer/Counter0 is externally clocked, the external signal is synchronized with the oscillator frequency of the CPU. To ensure proper sampling of the external clock, the minimum time between two external clock transitions must be at least one internal CPU clock period. The external clock signal is sampled on the rising edge of the internal CPU clock. The 8-bit Timer/Counter0 features both a high resolution and a high accuracy usage with the lower prescaling opportunities. Similarly, the high prescaling opportunities make the Timer/Counter0 useful for lower speed functions or exact timing functions with infrequent actions. 26 AT90S2323 CK/1024 AT90S2323 Figure 30. Timer/Counter 0 Block Diagram THE TIMER/COUNTER0 CONTROL REGISTER - TCCR0 Bit $33 ($53) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 R 0 3 R 0 2 CS02 R/W 0 1 CS01 R/W 0 0 CS00 R/W 0 TCCR0 Bits 7..3 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and always read zero. Bits 2,1,0 - CS02, CS01, CS00 : Clock Select0, bit 2,1 and 0: The Clock Select0 bits 2,1 and 0 define the prescaling source of Timer0. Table 7. Clock 0 Prescale Select CS02 0 0 0 0 1 1 1 1 CS01 0 0 1 1 0 0 1 1 CS00 0 1 0 1 0 1 0 1 Description Stop, the Timer/Counter0 is stopped. CK CK / 8 CK / 64 CK / 256 CK / 1024 External Pin T0, falling edge External Pin T0, rising edge The Stop condition provides a Timer Enable/Disable function. The CK down divided modes are scaled directly from the CK oscillator clock. If the external pin modes are used, the corresponding setup must be performed in the actual data direction control register (cleared to zero gives an input pin). 27 THE TIMER COUNTER 0 - TCNT0 Bit $32 ($52) Read/Write Initial value 7 MSB R/W 0 R/W 0 R/W 0 R/W 0 R/W 0 R/W 0 R/W 0 6 5 4 3 2 1 0 LSB R/W 0 TCNT0 The Timer/Counter0 is realized as an up-counter with read and write access. If the Timer/Counter0 is written and a clock source is present, the Timer/Counter0 continues counting in the timer clock cycle following the write operation. The Watchdog Timer The Watchdog Timer is clocked from a separate on-chip oscillator which runs at 1MHz This is the typical value at VCC = 5V. See characterization data for typical values at other VCC levels. By controlling the Watchdog Timer prescaler, the Watchdog reset interval can be adjusted from 16 to 2048 ms. The WDR - Watchdog Reset - instruction resets the Watchdog Timer. Eight different clock cycle periods can be selected to determine the reset period. If the reset period expires without another Watchdog reset, the AT90S2323 resets and executes from the reset vector. For timing details on the Watchdog reset, refer to Page 21. To prevent unintentional disabling of the watchdog, a special turn-off sequence must be followed when the watchdog is disabled.Refer to the description of the Watchdog Timer Control Register for details. Figure 31. Watchdog Timer THE WATCHDOG TIMER CONTROL REGISTER - WDTCR Bit $21 ($41) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 WDTOE R/W 0 3 WDE R/W 0 2 WDP2 R/W 0 1 WDP1 R/W 0 0 WDP0 R/W 0 WDTCR Bits 7..5 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and will always read as zero. Bit 4 - WDTOE : Watch Dog Turn-Off Enable: This bit must be set (one) when the WDE bit is cleared. Otherwise, the watchdog will not be disabled. Once set, hardware will clear this bit to zero after four clock cycles. Refer to the description of the WDE bit for a watchdog disable procedure. 28 AT90S2323 AT90S2323 Bit 3 - WDE : Watch Dog Enable: When the WDE is set (one) the Watchdog Timer is enabled, and if the WDE is cleared (zero) the Watchdog Timer function is disabled. WDE can only be cleared if the WDTOE bit is set(one). To disable an enabled watchdog timer, the following procedure must be followed: 1. In the same operation, write a logical one to WDTOE and WDE. A logcal one must be written to WDE even though it is set to one before the disable operation starts. 2. Within the next four clock cycles, write a logical 0 to WDE. This disables the watchdog. Bits 2..0 - WDP2, WDP1, WDP0 : Watchdog Timer Prescaler 1 and 0: The WDP2, WDP1 and WDP0 bits determine the Watchdog Timer prescaling when the Watchdog Timer is enabled. The different prescaling values and their corresponding time-out periods are shown in Table 8. Table 8. Watch Dog Timer Prescale Select (Typical Values at VCC = 5.0V) WDP2 0 0 0 0 1 1 1 1 WDP1 0 0 1 1 0 0 1 1 WDP0 0 1 0 1 0 1 0 1 Time-out Period 16 ms 32 ms 64 ms 128 ms 256 ms 512 ms 1024 ms 2048 ms EEPROM Read/Write Access The EEPROM access registers are accessible in the I/O space. The write access time is in the range of 2.5 - 4ms, depending on the VCC voltages. A self-timing function, however, lets the user software detect when the next byte can be written. An EEPROM brown-out detection prevents writing to the EEPROM if VCC is below a certain level. In order to prevent unintentional EEPROM writes, a specific write procedure must be followed. Refer to the description of the EEPROM Control Register for details on this. When the EEPROM is read or written, the CPU is halted for two clock cycles before the next instruction is executed. THE EEPROM ADDRESS REGISTER - EEAR Bit $1E ($3E) Read/Write Initial value 7 R 0 6 EEAR6 R/W 0 5 EEAR5 R/W 0 4 EEAR4 R/W 0 3 EEAR3 R/W 0 2 EEAR2 R/W 0 1 EEAR1 R/W 0 0 EEAR0 R/W 0 EEAR Bit 7 - Res : Reserved bit: This bit is a reserved bit in the AT90S2323 and will always read as zero. Bit 6..0 - EEAR6..0 : EEPROM Address: The EEPROM Address Register - EEAR6..0 - specifies the EEPROM address in the 128 bytes EEPROM space. The EEPROM data bytes are addressed linearly between 0 and 127. 29 THE EEPROM DATA REGISTER - EEDR Bit $1D ($3D) Read/Write Initial value 7 MSB R/W 0 R/W 0 R/W 0 R/W 0 R/W 0 R/W 0 R/W 0 6 5 4 3 2 1 0 LSB R/W 0 EEDR Bit 7..0 - EEDR7..0 : EEPROM Data: For the EEPROM write operation, the EEDR register contains the data to be written to the EEPROM in the address given by the EEAR register. For the EEPROM read operation, the EEDR contains the data read out from the EEPROM at the address given by EEAR. THE EEPROM CONTROL REGISTER - EECR Bit $1C ($3C) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 R 0 3 R 0 2 EEMWE R/W 0 1 EEWE R/W 0 0 EERE R/W 0 EECR Bit 7..3 - Res : Reserved bits: These bits are reserved bits in the AT90S2323 and will always read as zero. Bit 2 - EEMWE : EEPROM Master Write Enable: The EEMWE bit determines whether setting EEWE to one causes the EEPROM to be written. When EEMWE is set(one) setting EEWE will write data to the EEPROM at the selected address If EEMWE is zero, setting EEWE will have no effect. When EEMWE has been set (one) by software, hardware clears the bit to zero after four clock cycles. See the description of the EEWE bit for a EEPROM write procedure. Bit 1 - EEWE : EEPROM Write Enable: The EEPROM Write Enable Signal EEWE is the write strobe to the EEPROM. When address and data are correctly set up, the EEWE bit must be set to write the value into the EEPROM. The EEMWE bit must be set when the logical one is written to EEWE, otherwise no EEPROM write takes place. The following procedure should be followed when writing the EEPROM (the order of steps 2 and 3 is unessential): 1. Wait until EEWE becomes zero. 2. Write new EEPROM address to EEAR (optional) 3. Write new EEPROM data to EEDR (optional) 4. Write a logical one to the EEMWE bit in EECR 5. Within four clock cycles after setting EEMWE, write a logical one to EEWE. When the write access time (typically 2.5 ms at VCC = 5V or 4 ms at V CC = 2.7V) has elapsed, the EEWE bit is cleared (zero) by hardware. The user software can poll this bit and wait for a zero before writing the next byte. When EEWE has been set, the CPU is halted for two cycles before the next instruction is executed. Bit 0 - EERE : EEPROM Read Enable: The EEPROM Read Enable Signal EERE is the read strobe to the EEPROM. When the correct address is set up in the EEAR register, the EERE bit must be set. When the EERE bit is cleared (zero) by hardware, requested data is found in the EEDR register. The EEPROM read access takes one instruction and there is no need to poll the EERE bit. When EERE has been set, the CPU is halted for two cycles before the next instruction is executed. The user should poll the EEWE bit before starting the read operation. If a write operation is in progress when new data or address is written to the EEPROM I/O registers, the write operation will be interrupted, and the result is undefined. I/O Port B Port B is an 5-bit bi-directional I/O port. 30 AT90S2323 AT90S2323 Three data memory address locations are allocated for Port B, one each for the Data Register - PORTB, $18 ($38), Data Direction Register - DDRB, $17($37) and the Port B Input Pins - PINB, $16($36). The Port B Input Pins address is read only, while the Data Register and the Data Direction Register are read/write. All port pins have individually selectable pullups. The Port B output buffers can sink 20mA and thus drive LED displays directly. When pins PB0 to PB4 are used as inputs and are externally pulled low, they will source current (IIL) if the internal pullups are activated. The Port B pins with alternate functions are shown in the following table: Table 9. Port B Pins Alternate Functions Port Pin PB0 PB1 PB2 PB3 PB4 Alternate Functions MOSI (Data input line for memory downloading) MISO (Data output line for memory uploading) INT0 (External Interrupt0 Input) SCK (Serial clock input for serial programming) TO (Timer/Counter0 counter clock input) XTAL1 (Oscillator input) XTAL2 (Oscillator output) When the pins are used for the alternate function the DDRB and PORTB register has to be set according to the alternate function description. THE PORT B DATA REGISTER - PORTB Bit $18 ($38) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 PORTB4 R/W 0 3 PORTB3 R/W 0 2 PORTB2 R/W 0 1 PORTB1 R/W 0 0 PORTB0 R/W 0 PORTB THE PORT B DATA DIRECTION REGISTER - DDRB Bit $17 ($37) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 DDB4 R/W 0 3 DDB3 R/W 0 2 DDB2 R/W 0 1 DDB1 R/W 0 0 DDB0 R/W 0 DDRB THE PORT B INPUT PINS ADDRESS - PINB Bit $16 ($36) Read/Write Initial value 7 R 0 6 R 0 5 R 0 4 PINB4 R Hi-Z 3 PINB3 R Hi-Z 2 PINB2 R Hi-Z 1 PINB1 R Hi-Z 0 PINB0 R Hi-Z PINB The Port B Input Pins address - PINB - is not a register, and this address enables access to the physical value on each Port B pin. When reading PORTB, the PORTB Data Latch is read, and when reading PINB, the logical values present on the pins are read. PORTB AS GENERAL DIGITAL I/O All 8 bits in port B are equal when used as digital I/O pins. PBn, General I/O pin: The DDBn bit in the DDRB register selects the direction of this pin, if DDBn is set (one), PBn is configured as an output pin. If DDBn is cleared (zero), PBn is configured as an input pin. If PORTBn is set (one) when the pin configured as an input pin, the MOS pull up resistor is activated. To switch the pull up resistor off, the PORTBn has to be cleared (zero) or the pin has to be configured as an output pin. 31 Table 10. DDBn Effects on Port B Pins DDBn 0 0 1 1 PORTBn 0 1 0 1 I/O Input Input Output Output Pull up No Yes No No Comment Tri-state (Hi-Z) PBn will source current (IIL) if ext. pulled low. Push-Pull Zero Output Push-Pull One Output n: 4,3...0, pin number. ALTERNATE FUNCTIONS OF PORTB The alternate pin functions of Port B are: XTAL2 - PORTB, Bit 4: XTAL2, Oscillator output, When the RCEN fuse is programmed and the device runs from the internal RC oscillator, this pin is a general I/O pin. When a crystal is used, the crystal must be connected between this pin and XTAL1. XTAL1 - PORTB, Bit 3: XTAL1, Oscillator input, When the RCEN fuse is programmed and the device runs from the internal RC oscillator, this pin is a general I/O pin. When a crystal is used, the crystal must be connected between this pin and XTAL2. Alternatively, an external clock source can be connected to XTAL1. SCK/T0 - PORTB, Bit2: In serial programming mode, this bit serves as the serial clock input, SCK During normal operation, this pin can serve as the external counter clock input. See the timer/counter description for further details. If external timer/counter clocking is selected, activity on this pin will clock the counter even if it is configured as an output. MISO - PORTB, Bit 1: In serial programming mode, this bit serves as the serial data output, MISO. During normal operation, this pin can serve as the external interrupt0 input. See the interrupt description for details on how to enable this interrupt. Note that activity on this pin will trigger the interrupt even if the pin is configured as an output. MOSI - PORTB, Bit 0: In serial programming mode, this pin serves as the serial data input, MOSI. Memory Programming Program Memory Lock Bits The AT90S2323 MCU provides two lock bits which can be left unprogrammed (`1') or can be programmed (`0') to obtain the additional features listed in Table 11. Table 11. Lock Bit Protection Modes Program Lock Bits Protection Type Mode 1 2 3 LB1 1 0 0 LB2 1 1 0 No program lock features Further programming of the Flash and EEPROM is disabled Same as mode 2, but verify is also disabled. Note: The Lock Bits can only be erased with the Chip Erase operation. Fuse Bits The AT90S2323 has two fuse bits, SPIEN and RCEN. 32 AT90S2323 AT90S2323 * When SPIEN is programmed (`0'), Serial Program Downloading is enabled. Default value is programmed (`0'). This bit is not accessible in the serial programming mode. * When RCEN is programmed (`0'), the internal RC oscillator is selected as the MCU clock source. Default value is programmed (`0'). When this status of this bit is changed in serial mode, the change occurs on the next power-on reset. Neither of these bits are affected by a chip erase. Signature Bytes All Atmel microcontrollers have a three-byte signature code which identifies the device. The three bytes reside in a separate address space, and for the AT90S2323 they are: 1. $000: $1E (indicates manufactured by Atmel) 2. $001: $91 (indicates 2 kB Flash memory) 3. $002: $02 (indicates 90S2323 device when $001 is $91) In serial mode, the signature bytes can not be read if lock mode 3 is enabled, i.e. both lock bits are programmed. In this case, the +12V Special Programming mode must be used. Programming the Flash and EEPROM Atmel's AT90S2323 offers 2K bytes of in-system reprogrammable Flash Program memory and 128 bytes of EEPROM Data memory. The AT90S2323 is normally shipped with the on-chip Flash Program and EEPROM Data memory arrays in the erased state (i.e. contents = $FF) and ready to be programmed. The device supports a Low-Voltage Serial programming mode. This mode provides a convenient way to download the Program and Data into the AT90S2323 inside the user's system. The Program and EEPROM memory arrays in the AT90S2323 are programmed byte-by-byte in either programming modes. For the EEPROM, an auto-erase cycle is provided with the self-timed programming operation in the serial programming mode. Some functions that are not accessible in serial programming mode, have to be performed in a +12V Special Programming mode. The +12V is used for programming enable only, and no current of significance is drawn by this pin. +12V Special Programming Mode This mode is used to perform functions that are not available in serial programming mode. These are: * Read Signature bytes in lock mode 3 * Program/Unprogram the SPIEN fuse. All shift operations described are MSB first and use XTAL1 as the clock. ENTER SPECIAL PROGRAMMING MODE 1. Apply 4.5 - 5.5 V between VCC and GND. 2. Set RESET and PB0 to `0'. 3. Toggle XTAL1 at least 8 times and leave it low(`0'). 4. Wait at least 100 ns. 5. Apply 12V to RESET and wait at least 100 ns. READING THE SIGNATURE BYTES 1. Give XTAL1 a negative pulse 2. Shift simulateneously the following values into PB0 and PB1: (Send MSB first, use XTAL1 as the shift clock) PB0:`0000 1000' PB1:`0100 1100' 3. Apply 3 negative pulses to XTAL1 4. Shift in simultaneously: PB0:`0000 0000' This is the address of signature byte #0. PB1:`0000 1100' 5. Apply 3 negative pulses to XTAL1 6. Shift `0000 0100' into PB1 33 7. Apply 3 negative pulses to XTAL1 8. Shift signature byte 0 out from PB2 9. Apply 3 negative pulses to XTAL1 10.Repeat Steps 3 - 9using addresses `0000 0001' and `0000 0010' for the following two signature bytes in Step 8. 11.Shift `0000 0000' into PB1 12.Apply 2 negative pulses to XTAL1 PROGRAMMING THE FUSE BITS 1. Give XTAL1 a negative pulse 2. Shift in simultaneously: PB0:`0100 0000' PB1:`0100 1100' 3. Apply 3 negative pulses to XTAL1 4. Shift in simultaneously: PB0:`00S0 000R'. S/R='1': SPIEN/RCEN unprogrammed, S/R='0' SPIEN/RCEN programmed PB1:`0100 1100' 5. Apply 3 negative pulses to XTAL1 6. Shift `0000 0100' into PB1 7. Apply 2 negative pulses to XTAL1 8. Wait 1 ms 9. Give XTAL1 a negative pulse 10.Shift `0000 1100' into PB1 11.Apply 2 negative pulses to XTAL1 12.Give XTAL1 a negative pulse 13.Shift data out of PB4. 14.Apply 2 negative pulses to XTAL1 15.Repeat steps 12- 14 until bit 1 in data shifted out goes high (`1') READING THE FUSE AND LOCK BITS 1. Give XTAL1 a negative pulse 2. Shift in simultaneously: PB0:`0000 1000' PB1:`0100 1100' 3. Apply 3 negative pulses to XTAL1 4. Shift `0001 0100' into PB1 5. Apply 3 negative pulses to XTAL1 6. Shift data out of PB4. The status of the fuse and lock bits is found in the following bits: Bit 7:Lock Bit1 (`0' means programmed) Bit 6:Lock Bit2 (`0' means programmed) Bit 5:SPIEN Fuse (`0' means programmed, `1' means unprogrammed) Bit 0:RCEN Fuse (`0' means programmed, `1' means unprogrammed) 7. Apply 3 negative pulses to XTAL1 8. Shift `0000 0000' into PB1 9. Apply 2 negative pulses to XTAL1 34 AT90S2323 AT90S2323 Low Voltage Serial Downloading Both the Program and Data memory arrays can be programmed using the serial SPI bus while RESET is pulled to GND. The serial interface consists of pins SCK, MOSI (input) and MISO (output). After RESET is set low, the Programming Enable instruction needs to be executed first before program/erase operations can be executed. When programming the EEPROM, an auto-erase cycle is built into the self-timed programming operation (in the serial mode ONLY) and there is no need to first execute the Chip Erase instruction. The Chip Erase operation turns the content of every memory location in both the Program and EEPROM arrays into $FF. The Program and EEPROM memory arrays have separate address spaces, $000 to $7FF for Program Flash memory and $000 to $07F for EEPROM Data memory. Either an external system clock is supplied at pin XTAL1 or a crystal needs to be connected across pins XTAL1 and XTAL2. The minimum low and high periods for the serial clock (SCK) input are defined as follows: Low: > 2 XTAL1 clock cycle High: > 2 XTAL1 clock cycles SERIAL PROGRAMMING ALGORITHM To program and verify the AT90S2323 in the serial programming mode, the following sequence is recommended (See four byte instruction formats in Table 12): 1. Power-up sequence: Apply power between VCC and GND while RESET and SCK are set to `0'. (If the programmer can not guarantee that SCK is held low during power-up, RESET must be given a positive pulse after SCK has been set to `0'.) If a crystal is not connected across pins XTAL1 and XTAL2, apply a 0 to 12 MHz clock to the XTAL1 pin. If the internal RC oscillator is selected as the clock source, no external clock source needs to be applied. 2. Wait for at least 20 ms and enable serial programming by sending the Programming Enable serial instruction to pin MOSI/PB0. Refer to the above section for minimum low and high periods for the serial clock input, SCK. 3. If a chip erase is performed (must be done to erase the Flash), wait 10ms, give RESET a positive pulse and start over again from Step 2. 4. The Flash or EEPROM array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. An EEPROM memory location is first automatically erased before new data is written. The next byte can be written after 4 ms. 5. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output MISO/PB1. At the end of the programming session, RESET can be set high to commence normal operation. 6. Power-off sequence (if needed): Set XTAL1 to `0' (if a crystal is not used). Set RESET to `1'. Turn VCC power off. Table 12. Serial Programming Instruction Set AT90S2323 Instruction Format Instruction Byte 1 Programming Enable Chip Erase Read Program Memory Write Program Memory Read EEPROM Memory 1010 1100 1010 1100 0010 H000 0100 H000 1010 0000 Byte 2 0101 0011 100x xxxx 0000 00aa 0000 00aa 0000 0000 Byte 3 xxxx xxxx xxxx xxxx bbbb bbbb bbbb bbbb xbbb bbbb Byte4 xxxx xxxx xxxx xxxx oooo oooo iiii iiii oooo oooo Enable Serial Programming after RESET goes low. Chip erase both 2K & 128 byte memory arrays Read H(high or low) data o from Program memory at word address a:b Write H(high or low) data i to Program memory at word address a:b Read data o from EEPROM memory at address b Operation 35 Write EEPROM Memory Read Lock and Fuse Bits Write Lock Bits Write RCEN Bit Read Device Code 1100 0000 0101 1000 1010 1100 1010 1100 0011 0000 0000 0000 xxxx xxxx 111x x21x 101x xxxR xxxx xxxx xbbb bbbb xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxbb iiii iiii 00S0 x21R xxxx xxxx xxxx xxxx oooo oooo Write data i to EEPROM memory at address b Read lock and fuse bits. `0': Programmed, `1': Unprogrammed Write lock bits. Set bits 1,2='0' to program lock bits. Write RCEN fuse. Set bit R='0' to program fuse, `1' to unprogram(3) Read Device Code o from address b(2). Notes: 1. a = address high bits b = address low bits H = 0 - Low byte, 1- High byte o = data out i = data in x = don't care 1 = lock bit 1 2 = lock bit 2 R = RCEN Fuse S = SPIEN Fuse 2 3 The device code is not readable in lock mode 3, i.e. both lock bits programmed When the state of the RCEN bit is changed in serial programming mode, the device must be power cycled for the changes to have any effect. AT90S2323 GND RESET XTAL1 XTAL2 GND VCC PB2(SCK) PB1(MISO) PB0(MOSI) 2.7 - 6.0V 1 to 12 MHz CLOCK IN DATA OUT INSTR. IN Figure 32. Serial Programming and Verify When writing serial data to the AT90S2323, data is clocked on the rising edge of CLK. When reading data from the AT90S2323, data is clocked on the falling edge of CLK. See Figure 33 for an explanation. 36 AT90S2323 AT90S2323 Programming Characteristics Figure 33. Serial Downloading Waveforms Absolute Maximum Ratings Operating Temperature.........................-55C to +125C Storage Temperature............................-65C to +150C Voltage on any Pin except RESET with respect to Ground ............................ -1.0V to +7.0V Maximum Operating Voltage ...................................6.6V DC Current per I/O Pin ......................................40.0 mA DC Current VCC and GND Pins......................140.0 mA *NOTICE: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 37 DC Characteristics TA = -40C to 85C, VCC = 2.7V to 6.0V (unless otherwise noted) Symbol VIL VIH VIH1 VOL VOH IOH IIL RRST RI/O Parameter Input Low Voltage Input High Voltage Input High Voltage Output Low Voltage Output High Voltage Output Source Current (1) Condition Min -0.5 Typ Max 0.2 Vcc - 0.1 VCC + 0.5 VCC + 0.5 0.5 Units V V V V V (Except XTAL1, RESET) (XTAL1, RESET) IIL = 25 mA, V CC = 5V IIL = 15 mA, V CC = 3V IOH = 3 mA, VCC = 5V IOH = 3 mA, VCC = 3V VCC = 5V, VOH = 4.5V VCC = 3V, VOH = 2.7V VCC = 5V, VOL = 0.5V VCC = 3V, VOL = 0.3V 0.2 VCC + 0.9 0.7 VCC VCC - 0.5 4 2 28 11 100 35 500 120 1.1 600 10 0.15 15 1 mA Output Sink Current Reset Pull-Up Resistor I/O Pin Pull-Up Resistor mA k k mA A A A Active Mode, 3V, 4MHz Idle Mode 3V, 4MHz ICC Power Supply Current Power Down WDT enabled, 3V Power Down (2) WDT disabled, 3V (2) Notes: 1. Under steady state (non-transient) conditions, IOL must be externally limited as follows: Maximum IOL per port pin: 20mA Maximum total IOL for all output pins: 80mA If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test conditions. 2. Minimum VCC for Power Down is 2V. 38 AT90S2323 AT90S2323 AT90S2323 Register Summary Address $3F ($5F) $3E ($5E) $3D ($5D) $3C ($5C) $3B ($5B) $3A ($5A) $39 ($59) $38 ($58) $37 ($57) $36 ($56) $35 ($55) $34 ($54) $33 ($53) $32 ($52) $31 ($51) $30 ($50) $2F ($4F) $2E ($4E) $2D ($4D) $2C ($4C) $2B ($4B) $2A ($4A) $29 ($49) $28 ($48) $27 ($47) $26 ($46) $25 ($45) $24 ($44) $23 ($43) $22 ($42) $21 ($41) $20 ($40) $1F ($3F) $1E ($3E) $1D ($3D) $1C ($3C) $1B ($3B) $1A ($3A) $19 ($39) $18 ($38) $17 ($37) $16 ($36) $15 ($35) $14 ($34) $13 ($33) $12 ($32) $11 ($31) $10 ($30) $0F ($2F) $0E ($2E) $0D ($2D) $0C ($2C) $0B ($2B) $0A ($2A) $09 ($29) $08 ($28) ... $00 ($20) Name SREG Reserved SPL Reserved GIMSK GIFR TIMSK TIFR Reserved Reserved MCUCR MCUSR TCCR0 TCNT0 Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved WDTCR Reserved Reserved EEAR EEDR EECR Reserved Reserved Reserved PORTB DDRB PINB Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Bit 7 I SP7 - Bit 6 T SP6 INT0 INTF0 - Bit 5 H SP5 - Bit 4 S SP4 - Bit 3 V SP3 - Bit 2 N SP2 - Bit 1 Z SP1 TOIE0 TOV0 Bit 0 C SP0 - Page 16 17 22 23 23 23 Timer/Counter0 (8 Bit) SE - SM - - CS02 ISC01 EXTRF CS01 ISC00 PORF CS00 24 21 27 28 - - - WDTOE WDE WDP2 WDP1 WDP0 28 EEPROM Address Register EEPROM Data register - - - EEMWE EEWE EERE 29 30 30 - - - PORTB4 DDB4 PINB4 PORTB3 DDB3 PINB3 PORTB2 DDB2 PINB2 PORTB1 DDB1 PINB1 PORTB0 DDB0 PINB0 31 31 31 39 AT90S2323 Instruction Set Summary Mnemonics Operands Description Operation Rd Rd + Rr Rd Rd + Rr + C Rdh:Rdl Rdh:Rdl + K Rd Rd - Rr Rd Rd - K Rdh:Rdl Rdh:Rdl - K Rd Rd - Rr - C Rd Rd - K - C Rd Rd * Rr Rd Rd * K Rd Rd v Rr Rd Rd v K Rd Rd Rr Rd $FF - Rd Rd $00 - Rd Rd Rd v K Rd Rd * ($FF - K) Rd Rd + 1 Rd Rd - 1 Rd Rd * Rd Rd Rd Rd Rd $FF PC PC + k + 1 PC Z PC PC + k + 1 PC Z PC STACK PC STACK if (Rd = Rr) PC PC + 2 or 3 Flags Z,C,N,V,H Z,C,N,V,H Z,C,N,V,S Z,C,N,V,H Z,C,N,V,H Z,C,N,V,S Z,C,N,V,H Z,C,N,V,H Z,N,V Z,N,V Z,N,V Z,N,V Z,N,V Z,C,N,V Z,C,N,V,H Z,N,V Z,N,V Z,N,V Z,N,V Z,N,V Z,N,V None None None None None None I None Z, N,V,C,H Z, N,V,C,H Z, N,V,C,H None None None None None None None None None None None None None None None None None None None None None None None None #Clocks 1 1 2 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 3 3 4 4 1/2 1 1 1 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 ARITHMETIC AND LOGIC INSTRUCTIONS ADD Rd, Rr Add two Registers ADC Rd, Rr Add with Carry two Registers ADIW Rdl,K Add Immediate to Word SUB Rd, Rr Subtract two Registers SUBI Rd, K Subtract Constant from Register SBIW Rdl,K Subtract Immediate from Word SBC Rd, Rr Subtract with Carry two Registers SBCI Rd, K Subtract with Carry Constant from Reg. AND Rd, Rr Logical AND Registers ANDI Rd, K Logical AND Register and Constant OR Rd, Rr Logical OR Registers ORI Rd, K Logical OR Register and Constant EOR Rd, Rr Exclusive OR Registers COM Rd One's Complement NEG Rd Two's Complement SBR Rd,K Set Bit(s) in Register CBR Rd,K Clear Bit(s) in Register INC Rd Increment DEC Rd Decrement TST Rd Test for Zero or Minus CLR Rd Clear Register SER Rd Set Register BRANCH INSTRUCTIONS RJMP k Relative Jump IJMP Indirect Jump to (Z) RCALL k Relative Subroutine Call ICALL Indirect Call to (Z) RET Subroutine Return RETI Interrupt Return CPSE Rd,Rr Compare, Skip if Equal CP Rd,Rr Compare CPC Rd,Rr Compare with Carry CPI Rd,K Compare Register with Immediate SBRC Rr, b Skip if Bit in Register Cleared SBRS Rr, b Skip if Bit in Register is Set SBIC P, b Skip if Bit in I/O Register Cleared SBIS P, b Skip if Bit in I/O Register is Set BRBS s, k Branch if Status Flag Set BRBC s, k Branch if Status Flag Cleared BREQ k Branch if Equal BRNE k Branch if Not Equal BRCS k Branch if Carry Set BRCC k Branch if Carry Cleared BRSH k Branch if Same or Higher BRLO k Branch if Lower BRMI k Branch if Minus BRPL k Branch if Plus BRGE k Branch if Greater or Equal, Signed BRLT k Branch if Less Than Zero, Signed BRHS k Branch if Half Carry Flag Set BRHC k Branch if Half Carry Flag Cleared BRTS k Branch if T Flag Set BRTC k Branch if T Flag Cleared BRVS k Branch if Overflow Flag is Set BRVC k Branch if Overflow Flag is Cleared BRIE k Branch if Interrupt Enabled BRID k Branch if Interrupt Disabled Rd - Rr Rd - Rr - C Rd - K if (Rr(b)=0) PC PC + 2 or 3 if (Rr(b)=1) PC PC + 2 or 3 if (P(b)=0) PC PC + 2 or 3 if (R(b)=1) PC PC + 2 or 3 if (SREG(s) = 1) then PCPC + k + 1 if (SREG(s) = 0) then PCPC + k + 1 if (Z = 1) then PC PC + k + 1 if (Z = 0) then PC PC + k + 1 if (C = 1) then PC PC + k + 1 if (C = 0) then PC PC + k + 1 if (C = 0) then PC PC + k + 1 if (C = 1) then PC PC + k + 1 if (N = 1) then PC PC + k + 1 if (N = 0) then PC PC + k + 1 if (N V= 0) then PC PC + k + 1 if (N V= 1) then PC PC + k + 1 if (H = 1) then PC PC + k + 1 if (H = 0) then PC PC + k + 1 if (T = 1) then PC PC + k + 1 if (T = 0) then PC PC + k + 1 if (V = 1) then PC PC + k + 1 if (V = 0) then PC PC + k + 1 if ( I = 1) then PC PC + k + 1 if ( I = 0) then PC PC + k + 1 (continued) 40 AT90S2323 AT90S2323 Mnemonics Operands Description Move Between Registers Load Immediate Load Indirect Load Indirect and Post-Inc. Load Indirect and Pre-Dec. Load Indirect Load Indirect and Post-Inc. Load Indirect and Pre-Dec. Load Indirect with Displacement Load Indirect Load Indirect and Post-Inc. Load Indirect and Pre-Dec. Load Indirect with Displacement Load Direct from SRAM Store Indirect Store Indirect and Post-Inc. Store Indirect and Pre-Dec. Store Indirect Store Indirect and Post-Inc. Store Indirect and Pre-Dec. Store Indirect with Displacement Store Indirect Store Indirect and Post-Inc. Store Indirect and Pre-Dec. Store Indirect with Displacement Store Direct to SRAM Load Program Memory In Port Out Port Push Register on Stack Pop Register from Stack Set Bit in I/O Register Clear Bit in I/O Register Logical Shift Left Logical Shift Right Rotate Left Through Carry Rotate Right Through Carry Arithmetic Shift Right Swap Nibbles Flag Set Flag Clear Bit Store from Register to T Bit load from T to Register Set Carry Clear Carry Set Negative Flag Clear Negative Flag Set Zero Flag Clear Zero Flag Global Interrupt Enable Global Interrupt Disable Set Signed Test Flag Clear Signed Test Flag Set Twos Complement Overflow Clear Twos Complement Overflow Set T in SREG Clear T in SREG Set Half Carry Flag in SREG Clear Half Carry Flag in SREG No Operation Sleep Watchdog Reset Operation Rd Rr Rd K Rd (X) Rd (X), X X + 1 X X - 1, Rd (X) Rd (Y) Rd (Y), Y Y + 1 Y Y - 1, Rd (Y) Rd (Y + q) Rd (Z) Rd (Z), Z Z+1 Z Z - 1, Rd (Z) Rd (Z + q) Rd (k) (X) Rr (X) Rr, X X + 1 X X - 1, (X) Rr (Y) Rr (Y) Rr, Y Y + 1 Y Y - 1, (Y) Rr (Y + q) Rr (Z) Rr (Z) Rr, Z Z + 1 Z Z - 1, (Z) Rr (Z + q) Rr (k) Rr R0 (Z) Rd P P Rr STACK Rr Rd STACK I/O(P,b) 1 I/O(P,b) 0 Rd(n+1) Rd(n), Rd(0) 0 Rd(n) Rd(n+1), Rd(7) 0 Rd(0)C,Rd(n+1) Rd(n),CRd(7) Rd(7)C,Rd(n) Rd(n+1),CRd(0) Rd(n) Rd(n+1), n=0..6 Rd(3..0)Rd(7..4),Rd(7..4)Rd(3..0) SREG(s) 1 SREG(s) 0 T Rr(b) Rd(b) T C1 C0 N1 N0 Z1 Z0 I1 I0 S1 S0 V1 V0 T1 T0 H1 H0 (see specific descr. for Sleep function) (see specific descr. for WDR/timer) Flags None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None Z,C,N,V Z,C,N,V Z,C,N,V Z,C,N,V Z,C,N,V None SREG(s) SREG(s) T None C C N N Z Z I I S S V V T T H H None None None #Clocks 1 1 2 2 2 2 2 2 2 2 2 2 2 3 2 2 2 2 2 2 2 2 2 2 2 3 3 1 1 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 1 DATA TRANSFER INSTRUCTIONS MOV Rd, Rr LDI Rd, K LD Rd, X LD Rd, X+ LD Rd, - X LD Rd, Y LD Rd, Y+ LD Rd, - Y LDD Rd,Y+q LD Rd, Z LD Rd, Z+ LD Rd, -Z LDD Rd, Z+q LDS Rd, k ST X, Rr ST X+, Rr ST - X, Rr ST Y, Rr ST Y+, Rr ST - Y, Rr STD Y+q,Rr ST Z, Rr ST Z+, Rr ST -Z, Rr STD Z+q,Rr STS k, Rr LPM IN Rd, P OUT P, Rr PUSH Rr POP Rd BIT AND BIT-TEST INSTRUCTIONS SBI P,b CBI P,b LSL Rd LSR Rd ROL Rd ROR Rd ASR Rd SWAP Rd BSET s BCLR s BST Rr, b BLD Rd, b SEC CLC SEN CLN SEZ CLZ SEI CLI SES CLS SEV CLV SET CLT SEH CLH NOP SLEEP WDR 41 |
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