HD6433935 Hitachi, HD6433935 Datasheet - Page 181

• Manufacturer Part Number: HD6433935
• Description: 8-Bit MICROCONTROLLER
• Manufacturer: Hitachi

2. Port control register 8 (PCR8)
PCR8 is an 8-bit register for controlling whether each of the port 8 pins P8
input or output pin. Setting a PCR8 bit to 1 makes the corresponding pin an output pin, while
clearing the bit to 0 makes the pin an input pin.
Upon reset, PCR8 is initialized to H'00.
PCR8 is a write-only register, which is always read as all 1s.
8.9.3
Table 8-24 shows the port 8 pin functions.
Table 8-24 Port 8 Pin Functions
Pin
P8
8.9.4
Table 8-25 shows the port 8 pin states in each operating mode.
Table 8-25 Port 8 Pin States
Pins
P8
Bit
Initial value
Read/Write
7
7
to P8
to P8
0
0
Pin Functions
Pin States
Reset
High-
impedance
PCR8
Pin Functions and Selection Method
The pin function depends on bit PCR8
W
7
0
7
Pin function
Sleep
Retains
previous
state
PCR8
PCR8
W
6
0
n
6
PCR8
Subsleep
Retains
previous
state
W
5
0
5
PCR8
Standby
High-
impedance
W
4
0
P8
4
n
n
input pin
in PCR8.
0
PCR8
W
3
0
Watch
Retains
previous
state
3
PCR8
W
2
0
2
7
Subactive
Functional
to P8
PCR8
P8
W
1
0
0
n
functions as an
output pin
1
1
(n = 7 to 0)
Active
Functional
PCR8
W
0
0
0
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