20
•
Register Format
3.7
Interrupt Control Register
There are two different interrupt modes in PCI-7256. In the first mode, users
enable the COS interrupt function to monitor the enabled input channel’s
status whenever the status changes from 0 to 1 or 1 to 0. In the second
mode, users can select digital input channel 0, channel 1 or both channels as
the interrupt sources. In this mode, interrupt only assertes when the DI status
changes from 0 to 1, i.e., rising edge.
Because the two different modes
share the same interrupt signal in hardware, users are not allowed to
enable these two modes at the same time.
After processing the interrupt request event, users have to clear the interrupt
request in order to handle another interrupt request. To clear the interrupt
request, write 1 to the corresponding bit.
Address: BASE + 0x08
Attribute: Write
7
6
5
4
3
2
1
0
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CH1
CLR
CH0
CLR
COS
CLR
15
14
13
12
11
10
9
8
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CH1
Int_EN
CH0
Int_EN
COS
Int_EN
COS CLR (bit 0): write 1 to clear the COS interrupt.
1 : clear the COS interrupt
0 : no effect
CH0 CLR (bit 1): write 1 to clear DI channel 0 interrupt.
1 : clear DI channel 0 interrupt
0 : no effect
CH1 CLR (bit 2): write 1 to clear DI channel 1 interrupt.
1 : clear DI channel 1 interrupt
0 : no effect
COS Int_EN (bit 8): Write/Read
Change-of-State interrupt enable control
1 : enable
0 : disable
CH0 Int_EN (bit 9): Write/Read
DI channel 0 interrupt enable control
1 : enable
0 : disable
