4-80

FIGURE 6. CDP1874C USED AS AN INPUT PORT AND ADDRESS LATCH WITH CDP1875C USED AS AN OUTPUT PORT

FIGURE 7. CDP1872C USED AS AN INPUT PORT AND SELECTED BY CD74HC138

CSI

DATA BUS

CS2

D7

D6

D5

D4

D3

D2

D1

D0

CDP1874C

CLOCK

ADDRESS BUS

CS2

DI

CDP1874C

CLOCK

0 - 7

TPB

MA15

MA8

TPA

CDP1802

MRD

CSI

DO

DATA IN

CS1

DO

CDP1875C

CS2

DI

DATA OUT

CS3

DATA BUS

•

•

•

Y7

Y6

Y5

Y4

Y3

Y2

Y1

CD74HC138

CS1

CDP1872C

CLOCK

N2

N1

N0

CDP1802A

CS2

DATA IN

CDP1872C

CS2

DATA OUT

CS1

DATA BUS

CLOCK

A2

A1

A0

MRD

D0 - D7

DATA BUS

CDP1872C, CDP1874C, CDP1875C