Three different Single-Chip 8-Bit Microcontroller families are presented in this datasheet:
For applications requiring 4K ROM/EPROM, see the 8XC51/80C31 8-bit CMOS (low voltage, low power, and high speed) microcontroller families datasheet.
All the families are Single-Chip 8-Bit Microcontrollers manufactured in advanced CMOS process and are derivatives of the 80C51 microcontroller family. All the devices have the same instruction set as the 80C51.
These devices provide architectural enhancements that make them applicable in a variety of applications for general control systems.
The ROMless devices, 80C51FA, and 80C51RA+ can address up to 64K of external memory. All the devices have four 8-bit I/O ports, three 16-bit timer/event counters, a multi-source, four-priority-level, nested interrupt structure, an enhanced UART and on-chip oscillator and timing circuits. For systems that require extra memory capability up to 64k bytes, each can be expanded using standard TTL-compatible memories and logic.
Its added features make it an even more powerful microcontroller for applications that require pulse width modulation, high-speed I/O and up/down counting capabilities such as motor control. It also has a more versatile serial channel that facilitates multiprocessor communications.