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General Purpose Input/Output
LH75400/01/10/11 (Preliminary) User’s Guide
21-4
6/17/03
21.2.3 GPIO Register Definitions
21.2.3.1 Port A Data Register
PADR is the Port A Data Register. The active bits used in this register are Read/Write.
Values written to PADR are output on the PA pins if the corresponding PADDR Data Direc-
tion bits are set HIGH (port output).
The values read from each bit of this register are determined by the value of the corre-
sponding bit in the Port A Data Direction Register (see Section 21.2.3.3). A read from this
register returns either:
• The last bit value written if the bit is configured as an output.
• The current value on the corresponding port input if the bit is configured as an input.
A System Reset clears all bits.
Table 21-3. PADR Register
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
///
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIELD
///
Port A Data
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
R
R
R
R
R
R
R
R
RW
RW
RW
RW
RW
RW
RW
RW
ADDR
0xFF 0x00
Table 21-4. PADR Register Definitions
BITS
NAME
FUNCTION
31:8
///
Reserved
Writing to these bits has no effect. Reading returns 0.
7:0
Port A Data
Port A Input/Output Data
Specifies Port A input or output data, depend-
ing on how the value of the corresponding bit in the PADDR Register is set
(see Section 21.2.3.3).
PADDR set as output = PADR sets the value on the GPIO Port A pins.
PADDR set as input = PADR reads the value on the GPIO Port A pins.