Fujitsu F2MCTM-16LX Hardware Manual page 187

Reading the port data register
The value obtained when reading the port data register (PDR) depends on the status of the port direction
register (DDR) and status of the peripheral function connected to the pin.
The following shows the value obtained by each combination.
Value of DDR
0 (input)
1 (output)
0 (input)
1 (output)
Further, when using as input by peripheral function, set the DDR of the connected pin to "0" (input).
Output state of peripheral
function
Enabled
Enabled
Disabled
Disabled
CHAPTER 10 I/O PORTS
Reading value
Output value from peripheral
function
Output value from peripheral
function
Pin state
Value of output latch
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