HD6433935 Hitachi, HD6433935 Datasheet - Page 186

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

2. Port control register A (PCRA)
PCRA controls whether each of port A pins PA
Setting a PCRA bit to 1 makes the corresponding pin an output pin, while clearing the bit to 0
makes the pin an input pin.
Upon reset, PCRA is initialized to H'F0.
PCRA is a write-only register, which always reads all 1s.
8.11.3
Table 8-30 shows the port A pin functions.
Table 8-30 Port A Pin Functions
Pin
PA
8.11.4
Table 8-31 shows the port A pin states in each operating mode.
Table 8-31 Port A Pin States
Pins
PA
174
Bit
Initial value
Read/Write
3
3
to PA
to PA
0
0
Pin States
Pin Functions
Reset
High-
impedance
Pin Functions and Selection Method
The pin function depends on bit PCRA
—
—
7
1
Pin function
Sleep
Retains
previous
state
PCRA
—
—
6
1
n
Subsleep
Retains
previous
state
—
—
5
1
3
to PA
Standby
High-
impedance
—
—
4
1
PA
0
n
functions as an input pin or output pin.
input pin
n
in PCRA.
0
PCRA
R/W
3
0
Watch
Retains
previous
state
3
PCRA
R/W
2
0
2
Subactive
Functional
PCRA
PA
R/W
1
0
n
output pin
1
1
Active
Functional
(n = 3 to 0)
PCRA
R/W
0
0
0