The Intel MCS-51 (commonly referred to as 8051) is a Harvard architecture, single chip microcontroller (µC) series which was developed by Intel in 1980 for use in embedded systems. Intel's original versions were popular in the 1980s and early 1990s. While Intel no longer manufactures the MCS-51, binary compatible derivatives remain popular today. In addition to these physical devices, several companies also offer MCS-51 derivatives as IP cores for use in FPGAs or ASICs designs.
Intel's original MCS-51 family was developed using NMOS technology, but later versions, identified by a letter C in their name (e.g., 80C51) used CMOS technology and consumed less power than their NMOS predecessors. This made them more suitable for battery-powered devices.
Read more about Intel MCS-51: Important Features and Applications, Memory Architecture, Programming, Instruction Set, Related Processors, Use As Intellectual Property, News MCU Base On 8051