
1998 National Semiconductor Corporation
P
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
I
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
I
On-Chip Memory
— 32K mask-programmed ROM program memory
— 2,784 bytes of static RAM data memory
I
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
and Phillips’ I
2
C bus
— 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
Clock
Generator
Power
Management
WATCHDOG
A/D
D/A
I/O Ports
Reset &
Configuration
Fan Speed
Counter
SMB Bus Ifc
Host Port
LAN
Interface
X
R
(
Registers
MII Standard
Interface
SMB Serial
Interface
Fan Inputs
NAND
Test
System
Events
GPIO
Analog
Channels
Multi-Input
Wake-Up
PFAIL
PRELIMINARY
March 1998
TRI-STATE is a registered trademark of National Semiconductor Corporation.
CompactRISC and WATCHDOG are trademarks of National Semiconductor Corporation.