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CHAPTER 5 PORT FUNCTIONS
5.2.5 Port 4
Port 4 is a 5-bit input/output port with output latch. P40 to P44 pins can specify the input mode/output mode in
1-bit units with the port mode register 4 (PM4).
Alternate functions also include timer input/output.
RESET input sets port 4 to input mode.
Figure 5-6 shows a block diagram of port 4.
Figure 5-6. P40 to P44 Block Diagram
PM
: Port mode register
RD
: Port 4 read signal
WR
: Port 4 write signal
RD
P40/TI00 to P42/TI02
P43/TIO2
P44/TIO3
WR
PORT
WR
PM
Output latch
(P40 to P44)
PM40 to PM44
Alternate
functions
Selector
Internal bus
Содержание mPD780973 Series
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