SC87C51ACF40 SIGNETICS MicroController 8-Bit UV EPROM ERASABLE NEW RARE $25 DESCRIPTION (PHILIPS SECOND SOURCE) The Philips 8XC51/31 is a high-performance static 80C51 design fabricated with Philips high-density CMOS technology with operation from 2.7V to 5.5V. The 8XC51/31 contains a 4k 8 ROM, a 128 8 RAM, 32 I/O lines, three 16-bit counter/timers, a six-source, four-priority level nested interrupt structure, a serial I/O port for either multi-processor communications, I/O expansion or full duplex UART, and on-chip oscillator and clock circuits.