Port 7 - NEC mPD789426 Series User Manual

4.2.7 Port 7

This is a 3-bit I/O port with an output latch. Port 7 can be specified in the input or output mode in 1-bit units by
using port mode register 7 (PM7). When using the P70 to P72 pins as input port pins, on-chip pull-up resistors can be
connected in 1-bit units by using pull-up resistor option register B7 (PUB7).
This port is set in the input mode when the RESET signal is input.
Figure 4-15 shows a block diagram of Port 7.
WR
PUB7
RD
WR
PORT
WR
PM
PUB7: Pull-up resistor option register B7
PM: Port mode register
RD: Port 7 read signal
WR: Port 7 write signal
CHAPTER 4 PORT FUNCTIONS
Figure 4-15. Block Diagram of P70 to P72
PUB70 to PUB72
Output latch
(P70 to P72)
PM70 to PM72
User's Manual U15075EJ1V0UM00
V
DD
P-ch
P70 to P72
93