Atmel AT89 series information

The Atmel AT89 series is an Intel 8051-compatible family of 8 bit microcontrollers (μCs) manufactured by the Atmel Corporation.

Based on the Intel 8051 core, the AT89 series remains very popular as general purpose microcontrollers, due to their industry standard instruction set, their low unit cost, and the availability of these chips in DIL (DIP) packages. This allows a great amount of legacy code to be reused without modification in new applications. While less powerful than the newer AT90 series of AVR RISC microcontrollers, new product development has continued with the AT89 series for the aforementioned advantages.

More recently, the AT89 series has been augmented with 8051-cored special function microcontrollers, specifically in the areas of USB, I²C (two wire interface), SPI and CAN bus controllers, MP3 decoders and hardware PWM.

Atmel has also created an LP (low power) series of these chips with a "Single Cycle Core", making the execution speed of these chips considerably faster.