Complete datasheet for the ATmega16 AVR microcontroller in a 2.73 MB PDF. Chapters cover the pinout, memory, clock options, timers, ADC, USART, SPI, TWI, JTAG, fuse and…

Atmel datasheet for the AT89S53, an 8051-compatible microcontroller with 12 KB of in-system programmable flash and SPI serial programming.

PDF datasheet for the Atmel AT89S51, an 8051-compatible microcontroller with 4 KB of in-system programmable flash and 128 bytes of RAM.

Datasheet for the KB9022Q, an ENE Technology keyboard and embedded controller found on many notebook motherboards, in a compact 137 KB PDF.

Datasheet in PDF form (127 KB) for the AT89C52, an Atmel microcontroller from the 8051-compatible family with on-chip flash program memory.