HD6473887 Datasheet, PDF (183/523 Pages) Renesas Technology Corp – Hitachi Single-Chip Microcomputer

2. Port control register 8 (PCR8)
Bit
Initial value
Read/Write
7
PCR8₇
0
W
6
PCR8₆
0
W
5
PCR8₅
0
W
4
PCR8₄
0
W
3
PCR8₃
0
W
2
PCR8₂
0
W
1
PCR8₁
0
W
0
PCR8₀
0
W
PCR8 is an 8-bit register for controlling whether each of the port 8 pins P8₇ to P8₀ functions as an
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. PCR8 and PDR8 settings are valid when the
corresponding pins are designated for general-purpose input/output by bits SGS3 to SGS0 in
LPCR.
Upon reset, PCR8 is initialized to H'00.
PCR8 is a write-only register, which is always read as all 1s.
8.9.3 Pin Functions
Table 8-24 shows the port 8 pin functions.
Table 8-24 Port 8 Pin Functions
Pin
P8₇/SEG₃₂
to P8₀/SEG₂₅
Pin Functions and Selection Method
The pin function depends on bit PCR8_n in PCR8 and bits SGS3 to SGS0 in
LPCR.
(n = 7 to 0)
SGS3 to SGS0
PCR8_n
Pin function
000*
0
1
P8_n input pin
P8_n output pin
001*, 01**,1***
*
SEG_n+25 output pin
*: Don’t care
8.9.4 Pin States
Table 8-25 shows the port 8 pin states in each operating mode.
Table 8-25 Port 8 Pin States
Pins
P8₇/SEG₃₂ to
P8₀/SEG₂₅
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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