Pio interrupt mask register, Pio interrupt status register – Rainbow Electronics AT75C220 User Manual
Page 73

AT75C220
73
PIO Interrupt Mask Register
Register Name:PIO_IMR
Access Type:Read-only
Reset Value:0
This register shows which pins have interrupts enabled. It is updated when interrupts are enabled or disabled by writing to
PIO_IER or PIO_IDR.
1 = Interrupt is enabled on the corresponding pin.
0 = Interrupt is not enabled on the corresponding pin.
PIO Interrupt Status Register
Register Name:PIO_ISR
Access Type:Read-only
Reset Value:0
This register indicates for each pin when a logic value change has been detected (rising or falling edge). This is valid
whether the PIO is selected for the pin or not and whether the pin is an input or an output.
The register is reset to zero following a read and at reset.
1 = At least one input change has been detected on the corresponding pin since the register was last read.
0 = No input change has been detected on the corresponding pin since the register was last read.
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