h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 285

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Port 8 Data Direction Register (P8DDR)
P8DDR is a 7-bit write-only register, the individual bits of which specify input or output for the
pins of port 8.
Setting a P8DDR bit to 1 makes the corresponding port 8 pin an output pin, while clearing the bit
to 0 makes the pin an input pin.
P8DDR is initialized to H'80 by a reset and in hardware standby mode. It retains its prior state in
software standby mode.
Port 8 Data Register (P8DR)
P8DR is a 7-bit readable/writable register that stores output data for the port 8 pins (P86 to P80). If
a port 8 read is performed while P8DDR bits are set to 1, the P8DR values are read directly,
regardless of the actual pin states. If a port 8 read is performed while P8DDR bits are cleared to 0,
the pin states are read.
P8DR is initialized to H'80 by a reset and in hardware standby mode. It retains its prior state in
software standby mode.
8.9.3
Port 8 pins also function as SCI1 I/O pins (TxD1, RxD1, SCK1), the IIC1 I/O pin (SCL1), HIF
I/O pins (CS2, GA20, HA0, HIFSD), and external interrupt input pins (IRQ5 to IRQ3). The port 8
pin functions are shown in table 8.18.
Bit
Initial value
Read/Write
Bit
Initial value
Read/Write
Pin Functions
—
—
—
—
7
1
7
1
P86DDR P85DDR P84DDR P83DDR P82DDR P81DDR P80DDR
P86DR
R/W
W
6
0
6
0
P85DR
R/W
W
5
0
5
0
P84DR
R/W
W
4
0
4
0
Rev. 4.00 Jun 06, 2006 page 231 of 1004
P83DR
R/W
W
3
0
3
0
P82DR
R/W
W
2
0
2
0
Section 8 I/O Ports
REJ09B0301-0400
P81DR
R/W
W
1
0
1
0
P80DR
R/W
W
0
0
0
0