Port 7 - NEC 78K0R/KE3 User Manual

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, and interrupt request input.
Reset signal generation sets port 7 to input mode.
Figure 4-22 shows a block diagram of port 7.
WR
PU
PU70 to PU77
RD
WR
PORT
Output latch
(P70 to P77)
WR
PM
PM70 to PM77
P7: Port register 7
PU7: Pull-up resistor option register 7
PM7: Port mode register 7
RD: Read signal
WR××: Write signal
CHAPTER 4 PORT FUNCTIONS
Figure 4-22. Block Diagram of P70 to P77
PU7
Alternate
function
P7
PM7
User's Manual U17854EJ9V0UD
EV
DD
P-ch
P70/KR0
to
P73/KR3,
P74/KR4/INTP8
to
P77/KR7/INTP11
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