Dallas Semiconductor

DS87C520MCL - High-Speed/Low-Power Microcontroller

Photograph

Features 80C52-compatible: 8051 pin- and instruction set-compatible Four 8-bit I/O ports Three 16-bit timer/counters 256 bytes scratchpad RAM 16kB On-Chip Program Memory High-speed architecture: 4 clocks/machine cycle (compared to 8051 = 12) DC to 33MHz (DS80C320) Single-cycle instruction in 121ns Dual data pointer Optional variable length MOVX to access fast/slow RAM /peripherals High-level integration: Power-fail reset Programmable watchdog timer Early-warning power-fail interrupt Two full-duplex hardware serial ports 13 total interrupt sources with six external

Pin Description Pin Number Description 1-8 Port 1 - I/O 9 RST - Reset Input 10-17 Port 3 - I/O 18 XTAL2 - Crystal 19 XTAL1 - Crystal 20 GND - Ground 21-28 Port 2 - I/O 29 PSEN - Output 30 ALE - Output 31 EA - Input 32-39 Port 0 - I/O 40 Vcc - +5V Supply

Pin Layout Dimensional Drawing

Technical Data Data Sheet Dallas Semiconductor - Data Sheet for DS87C520 Application Notes Dallas Semiconductor - App Note 102: Using the High-Speed Microcontroller as a Bootstrap Loader