Renesas H8S/2111B 用户手册
Rev. 1.00, 05/04, page 118 of 544
7.8 Port
8
Port 8 is an 8-bit I/O port. Port 8 pins also function as SCI_1 I/O pins, the IIC_1 I/O pins, LPC I/O
pins, and interrupt input pins. The output type of P86 and SCK1 is NMOS push-pull output. The
output type of SCL1 is NMOS open-drain output and direct bus driving is enabled. Port 8 has the
following registers.
pins, and interrupt input pins. The output type of P86 and SCK1 is NMOS push-pull output. The
output type of SCL1 is NMOS open-drain output and direct bus driving is enabled. Port 8 has the
following registers.
• Port 8 data direction register (P8DDR)
• Port 8 data register (P8DR)
• Port 8 data register (P8DR)
7.8.1
Port 8 Data Direction Register (P8DDR)
P8DDR specifies input or output for the pins of port 8 on a bit-by-bit basis.
Bit Bit
Name
Initial
Value
Value
R/W Description
7 —
1 — Reserved
The initial value should not be changed.
6 P86DDR
0 W
5 P85DDR
0 W
4 P84DDR
0 W
3 P83DDR
0 W
2 P82DDR
0 W
1 P81DDR
0 W
0 P80DDR
0 W
P8DDR has the same address as PBPIN, and if read,
the port B state will be returned.
the port B state will be returned.
The corresponding port 8 pins are output ports when
P8DDR bits are set to 1, and input ports when cleared
to 0.
P8DDR bits are set to 1, and input ports when cleared
to 0.
7.8.2
Port 8 Data Register (P8DR)
P8DR stores output data for the port 8 pins (P86 to P80).
Bit Bit
Name
Initial
Value R/W Description
Value R/W Description
7 —
1 — Reserved
The initial value should not be changed.
6 P86DR
0 R/W
5 P85DR
0 R/W
4 P84DR
0 R/W
3 P83DR
0 R/W
2 P82DR
0 R/W
1 P81DR
0 R/W
0 P80DR
0 R/W
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.
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.