Hitachi H8S/2646 Hardware Manual page 315

Hitachi 16-bit single-chip microcomputer h8s/2646 series
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Port F Data Register (PFDR)
Bit
:
7
Initial value :
0
R/W
:
R/W
PFDR is an 8-bit readable/writable register that stores output data for the port F pins (PF6 to PF2,
PF0).
PFDR is initialized to H'00 by a reset, and in hardware standby mode. It retains its prior state in
software standby mode.
Bits 7 and 1 in PFDR are reserved, and only 0 may be written to it.
Port F Register (PORTF)
Bit
:
7
PF7
Initial value :
—*
R/W
:
R
Note: * Determined by state of pins PF7 to PF2, PF0.
PORTF is an 8-bit read-only register that shows the pin states. It cannot be written to. Writing of
output data for the port F pins (PF7 to PF2, PF0) must always be performed on PFDR.
If a port F read is performed while PFDDR bits are set to 1, the PFDR values are read. If a port F
read is performed while PFDDR bits are cleared to 0, the pin states are read.
Pins used as LCD driver pins will return an undefined value if read.
After a reset and in hardware standby mode, PORTF contents are determined by the pin states, as
PFDDR and PFDR are initialized. PORTF retains its prior state in software standby mode.
PORTF bit 1 is reserved.
6
5
PF6DR
PF5DR
PF4DR
0
0
R/W
R/W
6
5
PF6
PF5
—*
—*
R
R
4
3
PF3DR
PF2DR
0
0
R/W
R/W
R/W
4
3
PF4
PF3
PF2
—*
—*
R
R
2
1
PF0DR
0
undefined
R/W
2
1
PF0
—*
—*
undefined
R
0
0
0
R
283

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