UPD78F0138 NEC, UPD78F0138 Datasheet - Page 108

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

4.2.8 Port 7
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).
108
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
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.
PU7:
PM7:
RD:
WR××: Write signal
WR
WR
WR
RD
PORT
PM
PU
Pull-up resistor option register 7
Port mode register 7
Read signal
Alternate function
PM70 to PM77
PU70 to PU77
(P70 to P77)
Output latch
PM7
PU7
Figure 4-17. Block Diagram of P70 to P77
CHAPTER 4 PORT FUNCTIONS
User’s Manual U16228EJ2V0UD
EV
DD
P-ch
P70/KR0 to
P77/KR7