CHAPTER 4 PORT FUNCTIONS
User’s Manual U16899EJ2V0UD
98
4.2.6 Port 5
Port 5 is a 4-bit I/O port with an output latch. Port 5 can be set to the input mode or output mode in 1-bit units
using port mode register 5 (PM5). Use of an on-chip pull-up resistor can be specified in 1-bit units using pull-up
resistor option register 5 (PU5).
RESET input sets port 5 to input mode.
Figure 4-15 shows a block diagram of port 5.
Figure 4-15. Block Diagram of P50 to P53
RD
P-ch
WR
PU
WR
PORT
WR
PM
EV
DD
P50 to P53
PU50 to PU53
Output latch
(P50 to P53)
PM50 to PM53
Selector
Internal bus
PU5
PM5
PU5:
Pull-up resistor option register 5
PM5:
Port mode register 5
RD: Read
signal
WR
××
: Write
signal