Digi NS7520B-1-C36 Hardware Reference Manual page 86

G E N m o d u l e r e g i s t e r s
The PORTA register configures the PORTA general-purpose input/output (GPIO) pins.
Each of the PORTA GPIO pins can be individually programmed — as general-purpose
input or output, or special function input or output — as applicable. Table 29
describes the PORTA register; Table 30 shows the different configurations for each
bit.
31 30
15 14
Register bit assignment
Bits
D31:24
D23:16
D15:08
Table 29: PORTA register bit definition
7 4
29 28 27 26
AMODE
13 12 11 10
Reserved
Access Mnemonic Reset
R/W AMODE 0
R/W ADIR 0
N/A Reserved N/A
N S 7 5 2 0 H a r d w a r e R e f e r e n c e , R e v G 9 / 2 0 0 7
25 24 23 22 21
9 8 7 6 5
Description
PORTA mode configuration
0 Selects GPIO mode
1 Selects special function mode
Configures the individual PORTA pins. Each bit in the
AMODE field corresponds to one of the PORTA bits; D31
controls PORTA7, D30 controls PORTA6, and so on.
PORTA data direction
0 Selects input mode
1 Selects output mode
Configures the individual PORTA pins. Each bit in the
ADIR field corresponds to one of the PORTA bits; D23
controls PORTA7, D22 controls PORTA6, and so on.
N/A
20 19 18 17 16
ADIR
4 3 2 1 0
ADATA