HD6433937 Datasheet, PDF (186/521 Pages) Hitachi Semiconductor – Hardware Manual

2. Port control register A (PCRA)
Bit
7
6
5
—
—
—
Initial value
1
1
1
Read/Write
—
—
—
4
3
2
1
0
—
PCRA ₃ PCRA ₂ PCRA ₁ PCRA ₀
1
0
0
0
0
—
R/W
R/W
R/W
R/W
PCRA controls whether each of port A pins PA₃ to PA₀ functions as an input pin or output pin.
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
Pin Functions
Table 8-30 shows the port A pin functions.
Table 8-30 Port A Pin Functions
Pin
PA₃ to PA₀
Pin Functions and Selection Method
The pin function depends on bit PCRA_n in PCRA.
PCRA_n
Pin function
0
PA_n input pin
(n = 3 to 0)
1
PA_n output pin
8.11.4 Pin States
Table 8-31 shows the port A pin states in each operating mode.
Table 8-31 Port A Pin States
Pins
PA₃ to PA₀
Reset
Sleep
High-
Retains
impedance previous
state
Subsleep
Retains
previous
state
Standby
High-
impedance
Watch
Retains
previous
state
Subactive Active
Functional Functional
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