NEC PD78055 Benutzerhandbuch

P-ch

WR

PM

WR

PORT

RD

WR

PUO

V

DD

Selector

PUO12

Output Latch
(P120 to P127)

PM120-PM127

Internal bus

P120/RTP0

P127/RTP7

This is an 8-bit input/output port with output latches.  Input mode/output mode can be specified bit-wise by means

of port mode register 12 (PM12).  When pins P120 to P127 are used as input port pins, an on-chip pull-up resistor

can be used as an 8-bit unit by means of pull-up resistor option register H (PUOH).

Alternate function includes real-time output.

RESET input sets the input mode.

Figure 6-17 shows a block diagram of port 12.

PUO :  Pull-up resistor option register

PM

:  Port mode register

RD

:  Port 12 read signal

WR :  Port 12 write signal