Recent chips from Cypress CY7C68013A (USB peripheral controller) to Ti CC2541 (a Bluetooth SoC) feature commodity 8051 cores, demonstrating that the Intel MCS-51 family design remains popular to this day. There's a plethora of derived MCUs by other manufacturers as well, even though Intel stopped producing this series of MCUs in March of 2007. First introduced in the 1980s, it's an 8-bit MCU like the 8048, but expands heavily on its feature set.
The functional block diagram as depicted in the Intel 80xxAH datasheet is shown as follows:
It's very similar to the Atmel (now microchip) AT89S51 which is still in production today. ...