4-49

should be selected so that operation is always within the following ranges:

PARAMETER

(V)

LIMITS

UNITS

CDP1855

CDP1855C

MIN

MAX

MIN

MAX

DC Operating Voltage Range

-

4

10.5

4

6.5

V

Input Voltage Range

-

V

Maximum Clock Input Frequency

5

3.2

-

3.2

-

MHz

10

6.4

-

-

-

MHz

Minimum 8 x 8 Multiply (16

÷ 8 Divide) Time

5

-

5.6

-

5.6

µs

10

-

2.8

-

-

µs

FIGURE 2. BLOCK DIAGRAM OF CDP1855 AND CDP1855C

22

BUS

7

21

BUS

6

20

BUS

5

19

BUS

4

18

BUS

3

17

BUS

2

16

BUS

1

15

BUS

0

11

REGISTER

SELECT LOGIC

12

13

1

SELECT CONTROL

SELECT Z

SELECT Y

SELECT X

SELECT STATUS

X SEQUENCE

COUNTER

RESET

OUT

8

CLOCK

26

CN1

27

CN0

8

ADD/

SUBTRACT

X REGISTER

LOAD

8

SHIFT

GENERATOR

Y REGISTER

LOAD

STATUS

REG

8

8

Y SEQUENCE

COUNTER

RESET

OUT

Z SEQUENCE

COUNTER

RESET

OUT

CHIP

NO.

SHIFT

RESET

Z REGISTER

LOAD

8

SHIFT

RESET

25

3

4

5

24

6

23

LOAD

10

7

2

9

RD/WE

SHIFT

CLEAR

STB

C.I.

CTL.

C.O./O.F.

RA2 RA1 RA0

CE

C.O.

14

CDP1855, CDP1855C