83C451

INTEGRATED CIRCUITS 80C451/83C451/87C451 80C51 8-bit microcontroller family 4K/128 OTP/ROM/ROMless, expanded I/O Product specification Supersedes data of 1998 Jan 19 IC20 Data Handbook 1998 May 01 Philips Semiconductors Philips Semiconductors Product specification 80C51 8-bit microcontroller family 4K/128 OTP/ROM/ROMless, expanded I/O 80C451/83C451/87C451 DESCRIPTION The Philips 8XC451 is an I/O expanded single-chip microcontroller fabricated with Philips high-density CMOS technology. Philips epitaxial substrate minimizes latch-up sensitivity. The 8XC451 (includes the 80C451, 87C451 and 83C451) is a functional extension of the 87C51 microcontroller with three additional I/O ports and four I/O control lines for a total of 68 pins. Four control lines associated with port 6 facilitate high-speed asynchronous I/O functions. The 8XC451 includes a 4k × 8 ROM (83C451) EPROM (87C451), a 128 × 8 RAM, 56 I/O, two 16-bit timer/counters, a five source, two priority level, nested interrupt structure, a serial I/O port for either a full duplex UART, I/O expansion, or multi-processor communications, and on-chip oscillator and clock circuits. The 80C451 ROMless version includes all of the 83C451 features except the on-board 4k × 8 ROM. The 87C451 has 4k of EPROM on-chip as program memory and is otherwise identical to the 83C451. The 8XC451 has two software selectable modes of reduced activity for further power reduction; idle mode and power-down mode. Idle mode freezes the CPU while a...