Advertisement
1004D–09/01
Figure 2. The AT90S/LS2323 Block Diagram
VCC
GND
PROGRAM
COUNTER
PROGRAM
FLASH
INSTRUCTION
REGISTER
INSTRUCTION
DECODER
CONTROL
LINES
PROGRAMMING
LOGIC
The AT90S2323/2343 provides the following features: 2K bytes of In-System Program-
mabl e Flash, 128 bytes EEPROM, 128 bytes SRAM, 3 (A T90S/LS2323)/5
(AT90S/LS2343) 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 nonvolatile memory technology.
The On-chip Flash allows the program memory to be reprogrammed in-system through
an SPI serial interface. By combining an 8-bit RISC CPU with ISP Flash on a monolithic
AT90S/LS2323/2343
8-BIT DATA BUS
INTERNAL
OSCILLATOR
STACK
WATCHDOG
POINTER
TIMER
MCU CONTROL
SRAM
REGISTER
GENERAL
TIMER/
PURPOSE
COUNTER
REGISTERS
X
INTERRUPT
Y
UNIT
Z
ALU
EEPROM
STATUS
REGISTER
SPI
DATA REGISTER
DATA DIR.
PORTB
REG. PORTB
PORTB DRIVERS
PB0 - PB2
TIMING AND
RESET
CONTROL
OSCILLATOR
3
Advertisement
