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