2. Port control register 8 (PCR8)
Bit
7
6
5
4
3
2
1
0
PCR87 PCR86 PCR85 PCR84 PCR83 PCR82
PCR81 PCR80
Initial value
Read/Write
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
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
Pin Functions and Selection Method
P87/SEG32
to P80/SEG25
The pin function depends on bit PCR8n in PCR8 and bits SGS3 to SGS0 in
LPCR.
(n = 7 to 0)
SGS3 to SGS0
PCR8n
000*
P8n output pin
001*, 01**,1***
*
0
1
Pin function
P8n input pin
SEGn+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
Reset
Sleep
Subsleep Standby
Watch
Subactive Active
P87/SEG32 to
P80/SEG25
High-
Retains
Retains
previous
state
High-
Retains
Functional
Functional
impedance previous
state
impedance previous
state
166
ETC [ ETC ]
