DESCRIPTION

The DS87C550 EPROM High-Speed Micro with A/D and PWM is a member of the fastest 100 8051-compatible microcontroller family available. It features a redesigned processor core that removes wasted clock and memory cycles. As a result, it executes 8051 instructions up to three times faster than the original architecture for the same crystal speed. The DS87C550 also offers a maximum crystal speed of 33 MHz, resulting in apparent execution speeds of up to 99 MHz.

FEATURES

■ 87C52-Compatible

- 8051 pin- and instruction set-compatible

- Three 16-bit timer/counters

- 256 bytes scratchpad RAM

■ On-chip Memory

- 8 kbytes EPROM (OTP & Windowed Packages)

- 1 kbyte extra on-chip SRAM for MOVX access

■ On-chip Analog to Digital Converter

- Eight channels of analog input, 10-bit resolution

- Fast conversion time

- Selectable internal or external reference voltage

■ Pulse Width Modulator Outputs

- Four channels of 8-bit PWM

- Channels cascadable to 16-bit PWM

■ 4 Capture + 3 Compare Registers

■ 55 I/O Port Pins

■ New Dual Data Pointer Operation

- Either data pointer can be incremented or

decremented

■ ROMSIZE Feature

- Selects effective on-chip ROM size from 0 to 8k

- Allows access to entire external memory map

- Dynamically adjustable by software

■ High-Speed Architecture

- 4 clocks/machine cycle (8051 = 12)

- Runs DC to 33 MHz clock rates

- Single-cycle instruction in 121 ns

- New Stretch Cycle feature allows access to

fast/slow memory or peripherals

■ Unique Power Savings Modes

■ EMI Reduction Mode disables ALE when not

needed

■ High integration controller includes:

- Power-fail reset

- Early-warning power-fail interrupt

- Two full-duplex hardware serial ports

- Programmable watchdog timer

■ 16 total interrupt sources with 6 external