FN2976 Rev.0.00

Page 1 of 21

March 1997

FN2976

Rev.0.00

March 1997

82C85

CMOS Static Clock Controller/Generator

DATASHEET

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

- C82C85. . . . . . . . . . . . . . . . . . . . . . . . . . 0oC to +70oC

- I82C85 . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to +85oC

- M82C85 . . . . . . . . . . . . . . . . . . . . . . . -55oC to +125oC

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 syn-

chronization 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

0oC to +70oCN28.45

IS82C85

-40oC to +85oCN28.45

CD82C85

24 Ld CERDIP

0oC to +70oC

F24.3

ID82C85

-40oC to +85oC

F24.3

MD82C85/B

-55oC to +125oC F24.3

MR82C85/B

28 Pad CLCC

-55oC to +125oC J28.A

CSYNC

PCLK

AEN1

RDY1

READY

RDY2

AEN2

CLK

GND

CLK50

START

SLO/FST

VCC

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

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