87C654

The 87C654 Single-Chip 8-Bit Microcontroller is manufactured in an advanced CMOS process and is a derivative of the 80C51 microcontroller family. The 87C654 has the same instruction set as the 80C51. Two versions of the derivative exist:
83C654-16k bytes mask programmable ROM
87C654-EPROM version
87C654 provides architectural enhancements that make it applicable in a variety of applications for general control
systems. The 87C654 contains a non-volatile 16k * 8 EPROM, a volatile 256 * 8 read/write data memory, four 8-bit I/O ports, two 16-bit timer/event counters (identical to the timers of the 80C51), a multi-source, two-priority-level, nested interrupt structure, an I2C interface, UART and on-chip oscillator and timing circuits. For systems that require extra capability, the 87C654 can be expanded using standard TTL compatible memories and logic.