AT89C55
4-169
PDIP
Features
• Compatible with MCS-51™ Products
• 20K Bytes of In-System Reprogrammable Flash Memory
– Endurance: 1,000 Write/Erase Cycles
• Fully Static Operation: 0 Hz to 33 MHz
• Three-Level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Eight Interrupt Sources
• Low Power Idle and Power Down Modes
Description
The AT89C55 is a low-power, high-performance CMOS 8-bit microcomputer with 20K
bytes of Flash programmable and erasable read only memory. The device is manu-
factured using Atmel’s high density nonvolatile memory technology and is compatible
with the industry standard 80C51 instruction set and pinout. The on-chip Flash allows
the program memory to be reprogrammed in-system or by a conventional nonvolatile
memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic
chip, the Atmel AT89C55 is a powerful microcomputer which provides a highly flexible
and cost effective solution to many embedded control applications.
0580D-A–12/97
8-Bit
Microcontroller
with 20K Bytes
Flash
AT89C55
Pin Configurations
PQFP/TQFP PLCC
(continued)