Rev. 1.0, 02/00, page 242 of 1141
Bit 1
P81/YB0 Pin Switching (PMRC1): PMRC1 sets whether to use the P81/YB0 pin as a
P81 I/O pin or a YB0 pin of the OSD character display position output.
Bit7
PMR1
Description
0
P81/YB0 pin functions as a P81 I/O pin
(Initial value)
1
P81/YB0 pin functions as a YB0 output pin
Port Control Register 8 (PCR8)
0
0
1
0
W
2
0
W
3
0
4
0
W
0
W
5
6
0
7
PCR84
PCR83
PCR82
PCR81
PCR80
0
W
PCR87
W
W
W
PCR86
PCR85
Bit :
Initial value :
R/W :
Port control register 8 (PCR8) controls I/O of pins P87 to P80 of port 8. The I/O is specified in a
unit of bit.
When PCR8 is set to 1, the corresponding P87 to P80 pins become output pins, and when it is set
to 0, they become input pins.
When the pins are set as general I/O pins, the settings of PCR8 and PDR8 become valid.
PCR8 is an 8-bit write-only register. When PCR8 is read, 1 is read. When reset PCR8 is initialized
to H'00.
Bits 7 to 0
P87 to P80 Pin I/O Switching
Bit n
PCR8n
Description
0
P8n pin functions as an input pin
(Initial value)
1
P8n pin functions as an output pin
(n = 7 to 0)