Atmel AT89C51RD2 Manuals

This document describes the features and characteristics of a product named Rev. 4235G–8051–08/05. The product is 80C52 compatible and features six 8-bit I/O ports (64 pins or 68 pins versions) or four 8-bit I/O ports (44 pins version), three 16-bit timer/counters, 256 bytes scratch pad RAM, 9 interrupt sources with 4 priority levels. Additionally, the product includes an integrated power monitor, supports ISP (In-System Programming), and has a high-speed architecture.

This document introduces the features of the AT89C51ED2 chip, including 80C52 compatibility, 8051 instruction compatibility, six 8-bit I/O ports, three 16-bit timers/counters, 256 bytes of erasable scratchpad RAM, 9 interrupt sources, 4 priority levels, integrated power monitor, ISP (in-system programming), 2048 bytes of boot ROM, etc.