HD6433044 Datasheet, PDF (270/867 Pages) Hitachi Semiconductor – Hitachi Single-Chip Microcomputer

ABWCR and P4DDR are not initialized in software standby mode. When port 4 functions as a
generic input/output port, if a P4DDR bit is set to 1, the corresponding pin maintains its output
state in software standby mode.
Port 4 Data Register (P4DR): P4DR is an 8-bit readable/writable register that stores output data
for pins P4₇ to P4₀. When a bit in P4DDR is set to 1, if port 4 is read the value of the
corresponding P4DR bit is returned. When a bit in P4DDR is cleared to 0, if port 4 is read the
corresponding pin level is read.
Bit
Initial value
Read/Write
7
P4 ₇
0
R/W
6
P4 ₆
0
R/W
5
P4 ₅
0
R/W
4
P4 ₄
0
R/W
3
P4 ₃
0
R/W
2
P4 ₂
0
R/W
1
P4 ₁
0
R/W
0
P4 ₀
0
R/W
Port 4 data 7 to 0
These bits store data for port 4 pins
P4DR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting.
Port 4 Input Pull-Up MOS Control Register (P4PCR): P4PCR is an 8-bit readable/writable
register that controls the MOS input pull-up transistors in port 4.
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0
P4₇PCR P4₆PCR P4₅PCR P4₄PCR P4₃PCR P4₂PCR P4₁PCR P4₀PCR
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Port 4 input pull-up MOS control 7 to 0
These bits control input pull-up MOS transistors built into port 4
In mode 7 (single-chip mode), and in 8-bit bus mode in modes 1 to 6 (expanded modes), when a
P4DDR bit is cleared to 0 (selecting generic input), if the corresponding P4PCR bit is set to 1, the
input pull-up MOS transistor is turned on.
P4PCR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting.
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