AT90S/LS2323 and AT90S/LS2343
Figure 2. The AT90S/LS2323 Block Diagram
8-BIT DATA BUS
PB0 - PB2
The AT90S/LS2323 and AT90S/LS2343 provides the fol-
lowing features: 2K bytes of In-System Programmable
Flash, 128 bytes EEPROM, 128 bytes SRAM, 3
(AT90S/LS2323) / 5 (AT90S/LS2343) general purpose I/O
lines, 32 general purpose working registers, an 8-bit
timer/counter, internal and external interrupts, programma-
ble 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 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 chip, the Atmel
AT90S/LS2323 and AT90S/LS2343 is a powerful micro-
controller that provides a highly flexible and cost effective
solution to many embedded control applications.
The AT90S/LS2323 and AT90S/LS2343 AVR is supported
with a full suite of program and system development tools
including: C compilers, macro assemblers, program debug-
ger/simulators, in-circuit emulators, and evaluation kits.
Comparison Between AT90S/LS2323
The AT90S/LS2323 is intended for use with external quartz
crystal or ceramic resonator as the clock source. The star-
tup time is fuse selectable as either 1 ms (suitable for
ceramic resonator) or 16 ms (suitable for crystal). The
device has three I/0 pins.
The AT90S/LS2343 is intended for use with either an exter-
nal clock source or the internal RC oscillator as clock
source. The device has five I/0 pins.