297

TM

March 1997

82C85

CMOS Static Clock Controller/Generator

Features

• Generates the System Clock For CMOS or NMOS

Microprocessors and Peripherals

• Complete Control Over System Operation for Very

Low System Power

- Stop-Oscillator

- Low Frequency

- Stop-Clock

- Full Speed Operation

• DC to 25MHz Operation (DC to 8MHz System Clock)

• Generates 50% and 33% Duty Cycle Clocks

(Synchronized)

• Uses a Parallel Mode Crystal Circuit or External

Frequency Source

• TTL Compatible Inputs/Outputs

• 24 Lead Slimline Dual-In-Line or 28 Pad Square LCC

Package Options

• Single 5V Power Supply

• Operating Temperature Range

Pinouts

24 LEAD CERDIP

TOP VIEW

Description

The Intersil 82C85 Static CMOS Clock Controller/Genera-

tor provides complete control of static CMOS system oper-

ating modes and supports full speed, slow, stop-clock and

stop-oscillator operation. While directly compatible with the

Intersil 80C86 and 80C88 16-bit Static CMOS Microproces-

sor Family, the 82C85 can also be used for general system

clock control.

For static system designs, separate signals are provided

on the 82C85 for stop (S0, S1, S2/STOP) and start

(START) control of the crystal oscillator and system clocks.

A single control line (SLO/FST) determines 82C85 fast

(crystal/EFI frequency divided by 3) or slow (crystal/EFI

frequency divided by 768) mode operation. Automatic

maximum

mode

80C86

and

80C88

software

HALT

instruction decode logic in the 82C85 enables software-

based clock control. Restart logic insures valid clock start-

up and complete synchronization of system clocks.

The 82C85 is manufactured using the Intersil advanced

Scaled SAJI IV CMOS process. In addition to clock control

circuitry, the 82C85 also contains a crystal controlled

oscillator (up to 25MHz), clock generation logic, complete

“Ready” synchronization and reset logic. This permits the

designer to tailor the system power-performance product to

provide optimum performance at low power levels.

28 LEAD PLCC, CLCC

TOP VIEW

Ordering Information

PART NUMBER

PACKAGE

TEMP. RANGE

PKG. NO.

CS82C85

28 Ld PLCC

IS82C85

CD82C85

24 Ld CERDIP

F24.3

ID82C85

F24.3

MD82C85/B

F24.3

MR82C85/B

28 Pad CLCC

CSYNC

PCLK

AEN1

RDY1

READY

RDY2

AEN2

CLK

GND

CLK50

START

SLO/FST

X2

ASYNC

EFI

F/C

RES

S2/STOP

S1

S0

X1

OSC

RESET

1

2

3

4

5

6

7

8

9

10

11

12

16

17

18

19

20

21

22

23

24

15

14

13

23

24

25

22

21

19

11

3

2

1

4

14 15 16 17 18

12 13

28 27 26

10

5

6

7

8

9

RDY1

READY

RDY2

AEN2

CLK

GND

NC

NC

ASYNC

EFI

F/C

OSC

RES

RESET

20

FN2976.1

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 321-724-7143

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