©1998 National Semiconductor Corporation

www.national.com

PC87782 CompactRISC Intelligent System Management

Controller

General Description

The PC87782 CompactRISC™ 16-bit Embedded Control-

ler is a highly integrated microcontroller designed for power

management applications in desktop Personal Computers

(PCs). The device is optimized for ACPI Power Manage-

ment, including multi-pattern Wake-up on LAN scanning;

and System Environment monitoring, including fan speed,

supply voltages, temperature and chassis intrusion. The

PC87782 incorporates National's CR16A CPU core (a

high-performance 16-bit RISC core), on-chip memories,

and system support functions.

The CR16A core offers the high performance of a RISC ar-

chitecture while retaining the advantages of a traditional

Complex Instruction Set Computer (CISC): compact code,

on-chip memory and I/O, and low cost. The CPU uses a

three-stage instruction pipeline that allows execution of up

to one instruction per clock cycle, or up to 20 million in-

structions per second (MIPS) at the maximum clock rate of

20 MHz.

Patent Pending.

Features

s CPU Features

— Fully static core, capable of operating at any rate

from 4 MHz to 20 MHz

— On-chip high-speed clock generator

— Multi-source vectored interrupts (internal, external,

and on-chip peripheral)

— On-chip power-on reset

s On-Chip Memory

— 32K mask-programmed ROM program memory

— 2,784 bytes of static RAM data memory

s On-Chip Peripherals

— Host Interface to PC (ISA and ACPI 1.0 compatible)

— 10/100 LAN Interface to monitor network traffic for

PC wake-up on LAN activity

— Fan-Speed Timer to monitor cooling fans

— System Management (ACCESS.bus) Interface, a 2-

wire serial interface compatible with Intel’s SMBus

— 8-channel, 8-bit Analog-to-Digital (A/D) converter

— 8-bit Digital-to-Analog (D/A) converter

— Integrated WATCHDOG™ logic

System Diagram

CR16A

Core

RAM

ROM

Core Bus

Peripheral Bus

Bus

Adaptor

32.768KHz

EC and PM

Host I/F

Processing

Unit

ICU

HF & LF

Generator

Clock

Power

Management

WATCHDOG

A/D

I/O Ports

Reset &

Configuration

Fan Speed

Counter

SMB Bus Ifc

Host Port

LAN

Registers

MII Standard

Interface

SMB Serial

Interface

Fan Inputs

NAND

Test

System

Events

GPIO

Analog

Channels

Multi-Input

Wake-Up

PFAIL

D/A

Interface

PRELIMINARY

March 1998

TRI-STATE® is a registered trademark of National Semiconductor Corporation.

CompactRISC™ and WATCHDOG™ are trademarks of National Semiconductor Corporation.