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6.4.3 Operations on input/output port
(1) Output mode
An operation is performed on the output latch contents, and the result is written to the output latch. The output
latch contents are output from the pins.
Once data is written to the output latch, it is retained until data is written to the output latch again.
(2) Input mode
The output latch contents are undefined, but since the output buffer is OFF, the pin status does not change.
Caution In the case of 1-bit memory manipulation instruction, although a single bit is manipulated, the
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CHAPTER 6 PORT FUNCTIONS
port is accessed as an 8-bit unit. Therefore, on a port with a mixture of input and output pins,
the output latch contents for pins specified as input are also undefined in addition to the
manipulated bit.
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