Port 7 - NEC mPD178054 Series User Manual

4.2.7 Port 7

Port 7 is an 8-bit I/O port with an output latch. Input or output mode can be specified for port 7 in 1-bit units using
port mode register 7 (PM7).
Alternate functions include serial interface data I/O, clock I/O, and timer input.
Reset input sets port 7 to the input mode.
Figures 4-12 to 4-15 show the block diagrams of port 7.
RD
WR
PORT
WR
PM
PM: Port mode register
RD: Port 7 read signal
WR: Port 7 write signal
CHAPTER 4 PORT FUNCTIONS
Figure 4-12. Block Diagram of P70, P74, and P77
Alternate function
Output latch
(P70, P74, P77)
PM70, PM74,
PM77
User's Manual U15104EJ2V0UD
P70/SI30
P74/SI31
P77/TI52
77