AT89C55

AT89C55 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 manufactured 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. (continued) 8-Bit Microcontroller with 20K Bytes Flash AT89C55 Pin Configurations PDIP PQFP/TQFP PLCC 0580D-A–12/97 4-169 Block Diagram P0.0 - P0.7 P2.0 - P2.7 VCC PORT 0 DRIVERS GND PORT 2 DRIVERS RAM ADDR. REGISTER RAM PORT 0 LATCH PORT 2 LATCH FLASH B REGISTER ACC STACK POINTER PROGRAM ADDRESS REGISTER BUFFER TMP2 TMP1 ALU INTERRUPT, SERIAL PORT, AND TIMER BLOCKS PC INCREMENTER PSW PROGRAM COUNTER PSEN ALE/PROG EA / VPP RST PORT 1 LATCH PORT 3 LAT...