4. Using the I/O Address Map
CNT16-8(FIT)GY, CNT16-8L(FIT)GY
21
Interrupt status
This is a common port on which the interrupt status requested by the Module can be verified.
Information on interrupt sources varies from module to module.
Starting
I/O
address
D7 D6 D5 D4 D3 D2 D1 D0
Input
Interruput Status
+2
(02h)
Enable
(0)
Status
(0)
0 0 0
IRQ 9
(0)
IRQ 7
(0)
IRQ 5
(0)
Figure 4.6. Interrupt Status
- Enable
[D7]:
This bit verifies the interrupt source enabled/disabled status.
The value "1" indicates that a hardware interrupt on the controller module is enabled.
- Status
[D6]:
This bit indicates an interrupt request status in the module. When an interrupt event has occurred in
the module and IRQ5, IRQ7, or IRQ9 is "1", this bit will also be "1".
-
IRQ* [D2 - D0]:
These bits allow you to verify the interrupt level that is currently set. The current interrupt level is
indicated as "1".
Setting an interrupt level
Starting
I/O
address
D7 D6 D5 D4 D3 D2 D1 D0
Output
Interruput Status
+2
(02h)
Enable
(0)
Status
(0)
0 0 0
IRQ 9
(0)
IRQ 7
(0)
IRQ 5
(0)
Figure 4.7. Setting an interrupt level
- Enable
[D7]:
This bit enables an interrupt source. Setting the bit to “1” enables hardware interrupts to the
controller module.
-
IRQ* [D2 - D0]:
The interrupt level used by the module is set in these bits. Setting any of the IRQs to “1” makes the
signal on that IRQ active upon reception of an interrupt request.