Pio status register, Pio output enable register – Rainbow Electronics AT75C220 User Manual
Page 68
AT75C220
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PIO Status Register
Register Name:PIO_PSR
Access Type:Read-only
This register indicates which pins are enabled for PIO control. This register is updated when PIO lines are enabled or dis-
abled.
1 = PIO is active on the corresponding line (peripheral is inactive).
0 = PIO is inactive on the corresponding line (peripheral is active).
PIO Output Enable Register
Register Name:PIO_OER
Access Type:Write-only
This register is used to enable PIO output drivers. If the pin is driven by a peripheral, there is no effect on the pin but the
information is stored. The register is programmed as follows:
1 = Enables the PIO output on the corresponding pin.
0 = No effect.
31
30
29
28
27
26
25
24
P31
P30
P29
P28
P27
P26
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0
31
30
29
28
27
26
25
24
P31
P30
P29
P28
P27
P26
P25
P24
23
22
21
20
19
18
17
16
P23
P22
P21
P20
P19
P18
P17
P16
15
14
13
12
11
10
9
8
P15
P14
P13
P12
P11
P10
P9
P8
7
6
5
4
3
2
1
0
P7
P6
P5
P4
P3
P2
P1
P0