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7.8.2 Register Descriptions
Table 7-11 summarizes the registers of port 8.
Table 7-11 Port 8 Registers
Address
*
Name
Abbreviation
R/W
Initial Value
H'FFCD
Port 8 data direction register
P8DDR
W
H'E0
H'FFCF
Port 8 data register
P8DR
R/W
H'E0
Note:
*
Lower 16 bits of the address.
Port 8 Data Direction Register (P8DDR): P8DDR is an 8-bit write-only register that can select
input or output for each pin in port 8.
7
—
1
—
6
—
1
—
5
—
1
—
4
—
0
W
3
—
0
W
2
—
0
W
1
P8 DDR
0
W
1
0
P8 DDR
0
W
0
Reserved bits
Port 8 data direction 1 and 0
These bits select input or
output for port 8 pins
Bit
Initial value
Read/Write
P8DDR is initialized to H'E0 by a reset and in hardware standby mode. In software standby mode
it retains its previous setting. If a P8DDR bit is set to 1, the corresponding pin maintains its output
state in software standby mode.
Port 8 Data Register (P8DR): P8DR is an 8-bit readable/writable register that stores data for pins
P8
1
to P8
0
.
Bit
Initial value
Read/Write
7
—
1
—
6
—
1
—
5
—
1
—
4
—
0
R/W
3
—
0
R/W
2
—
0
R/W
1
P8
0
R/W
1
0
P8
0
R/W
0
Reserved bits
Port 8 data 1 and 0
These bits store data
for port 8 pins
When a bit in P8DDR is set to 1, if port 8 is read the value of the corresponding P8DR bit is
returned directly. When a bit in P8DDR is cleared to 0, if port 8 is read the corresponding pin level
is read.