CHAPTER 4 PORT FUNCTIONS
User’s Manual U16899EJ2V0UD
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4.2.8 Port 7
Port 7 is an 8-bit I/O port with an output latch. Port 7 can be set to the input mode or output mode in 1-bit units
using port mode register 7 (PM7). When the P70 to P77 pins are used as an input port, use of an on-chip pull-up
resistor can be specified in 1-bit units by pull-up resistor option register 7 (PU7).
This port can also be used for key return input.
RESET input sets port 7 to input mode.
Figure 4-17 shows a block diagram of port 7.
Figure 4-17. Block Diagram of P70 to P77
P70/KR0 to
P77/KR7
WR
PU
RD
WR
PORT
WR
PM
PU70 to PU77
Alternate function
Output latch
(P70 to P77)
PM70 to PM77
EV
DD
P-ch
Selector
Internal bus
PU7
PM7
PU7:
Pull-up resistor option register 7
PM7:
Port mode register 7
RD: Read
signal
WR
××
: Write
signal