beautypg.com

NEC PD78F9488 User Manual

Page 85

background image

CHAPTER 4 PORT FUNCTIONS

User’s Manual U15331EJ4V1UD

85

Figure 4-10. Block Diagram of P34

(a) When

µPD789488, 78F9488 is used

P34

WR

PUB3

RD

WR

PORT

WR

PM

PUB34

PM34

V

DD

P-ch

Internal bus

Selector

Output latch

(P34)

(b) When

µPD789489, 78F9489 is used

P34/RIN

WR

PUB3

RD

WR

PORT

WR

PM

PUB34

PM34

V

DD

P-ch

Internal bus

Selector

Output latch

(P34)

Alternate

function

PUB3: Pull-up resistor option register B3
PM:

Port mode register

RD:

Port 3 read signal

WR:

Port 3 write signal

This manual is related to the following products: