Intel 8051 microcontroller family

Intel 8051 and 80C51 are members of Intel MCS-51 family of 8-bit microcontrollers. In addition to on-chip clock oscillator, 2 16-bit timers, 4 I/O ports and a serial port, all 8051 and 80C51 chips have 128 bytes of RAM and 4 KB masked ROM. If necessary, 8051 memory can be expanded up to 128 KB by adding up to 64 KB of external program and data memory.

Links
History
Architecture
Identification
Pinouts
Support chips
 Manufacturers 

Intel

Intel P8051AH
40-pin plastic DIP
Intel P8051AH

OKI

OKI M80C51-57
40-pin plastic DIP
OKI M80C51-57

Signetics

Signetics SCN8051H CCN40 (SCN8051HCCN40)
40-pin plastic DIP
Signetics SCN8051H CCN40 (SCN8051HCCN40)

USSR

USSR KR1816VE51
40-pin plastic DIP

Soviet clone of Intel 8051AH microcontroller
USSR KR1816VE51
(c) Copyright 2003 Gennadiy Shvets