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CHAPTER 5 PORT FUNCTIONS
User’s Manual U12697EJ3V0UM
5.2.9 Port 12
This is an 8-bit I/O port with output latch. Input mode/output mode can be specified in 1-bit units with the port 12
mode register. A pull-up resistor can be connected via pull-up resistor option register 12, regardless of whether the
input mode or output mode is specified.
Port 12 supports the real-time output function as an alternate function.
RESET input sets port 12 to the input mode.
Figure 5-18 shows a block diagram of port 12.
Figure 5-18. Block Diagram of P120 to P127
P-ch
WR
PM
WR
PORT
RD
WR
PU
V
DD
Selector
Alternate
function
PU120 to PU127
Output latch
(P120 to P127)
PM120 to PM127
Internal bus
P120/RTP0 to
P127/RTP7
PU:
Pull-up resistor option register
PM:
Port mode register
RD:
Port 12 read signal
WR: Port 12 write signal
