NEC uPD78P078 - Manual (Page 155)

155
CHAPTER 6 PORT FUNCTIONS
6.2.13 Port 12
This is an 8-bit input/output port with output latches. Input mode/output mode can be specified in 1-bit units with
the port mode register 12 (PM12). When pins P120 to P127 are used as input port pins, an on-chip pull-up resistor
can be connected in 8-bit units with a pull-up resistor option register H (PUOH).
These pins are dual function pin and serve as real-time outputs.
RESET input sets the input mode.
The port 12 block diagram is shown in Figure 6-22.
Figure 6-22. Block Diagram of P120 to P127
PUO : Pull-up resistor option register
PM : Port mode register
RD : Port 12 read signal
WR : Port 12 write signal
P-ch
WR PM
WR
PORT
RD
WR PUO
V
DD
Selector
PUO12
Output Latch
(P120 to P127)
PM120 to PM127
Internal bus
P120/RTP0 to
P127/RTP7