Manual
Table Of Contents
- Features
- Description
- Architectural Overview
- General-purpose Register File
- ALU – Arithmetic Logic Unit
- In-System Programmable Flash Program Memory
- EEPROM Data Memory
- SRAM Data Memory
- Program and Data Addressing Modes
- Register Direct, Single Register Rd
- Register Direct, Two Registers Rd and Rr
- I/O Direct
- Data Direct
- Data Indirect with Displacement
- Data Indirect
- Data Indirect with Pre- decrement
- Data Indirect with Post- increment
- Constant Addressing Using the LPM Instruction
- Indirect Program Addressing, IJMP and ICALL
- Relative Program Addressing, RJMP and RCALL
- Memory Access and Instruction Execution Timing
- I/O Memory
- Reset and Interrupt Handling
- Reset Sources
- Power-on Reset
- External Reset
- Watchdog Reset
- MCU Status Register – MCUSR
- Interrupt Handling
- General Interrupt Mask Register – GIMSK
- General Interrupt Flag Register – GIFR
- Timer/Counter Interrupt Mask Register – TIMSK
- Timer/Counter Interrupt FLAG Register – TIFR
- External Interrupt
- Interrupt Response Time
- MCU Control Register – MCUCR
- Sleep Modes
- Timer/Counter
- Watchdog Timer
- EEPROM Read/Write Access
- I/O Port B
- Memory Programming
- Electrical Characteristics
- Typical Characteristics
- AT90S2323/2343 Register Summary
- Ordering Information
- Packaging Information
38
AT90S/LS2323/2343
1004D–09/01
3. $002: $03 (indicates AT90S/LS2343 when signature byte $001 is $91)
Note: When both Lock bits are programmed (Lock mode 3), the signature bytes cannot be read
in the low-voltage Serial mode. Reading the signature bytes will return: $00, $01 and
$02.
Programming the Flash
and EEPROM
Atmel’s AT90S2323/2343 offers 2K bytes of In-System Programmable Flash program
memory and 128 bytes of EEPROM data memory.
The AT90S2323/2343 is 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 high-voltage (12V) Serial Programming mode and a low-voltage
Serial Programming mode. The +12V is used for programming enable only and no cur-
rent of significance is drawn by this pin. The low-voltage Serial Programming mode
provides a convenient way to download program and data into the device inside the
user’s system.
The program and EEPROM memory arrays in the AT90S2323/2343 are programmed
byte-by-byte in either programming modes. For the EEPROM, an auto-erase cycle is
provided within the self-timed write instruction in the low-voltage Serial Programming
mode.
During programming, the supply voltage must be in accordance with Table 15.
High-voltage Serial
Programming
This section describes how to program and verify Flash program memory, EEPROM
data memory, Lock bits and Fuse bits in the AT90S2323/2343.
Figure 32. High-voltage Serial Programming
Table 15. Supply Voltage during Programming
Part Low-voltage Serial Programming High-voltage Serial Programming
AT90S2323 4.0 - 6.0V 4.5 - 5.5V
AT90LS2323 2.7 - 6.0V 4.5 - 5.5V
AT90S2323 4.0 - 6.0V 4.5 - 5.5V
AT90LS2323 2.7 - 6.0V 4.5 - 5.5V
RESET
XTAL1/PB3
GND
VCC
PB2
PB1
PB0
SERIAL DATA OUTPUT
SERIAL INSTR. INPUT
SERIAL DATA INPUT
SERIAL CLOCK INPUT
11.5 - 12.5V 4.5 - 5.5V
AT90S/LS2323,
AT90S/LS2343