4. Interrupt Controller
36
Operational Registers (OCW1-OCW3)
The operation of each interrupt controller is managed by three 8-bit operational
registers. These registers are programmed in any sequence for things such as enabling
and disabling interrupt requests and changing interrupt priorities.
Input Mask
7
6
5
4
3
2
1
0
Register: OCW1
Address: Base + 1
Interrupt mask
Access: Read and Write
0 Reset
1 Set
Operational Register OCW1
Level
Mode
7
6
5
4
3
2
1
0
Register: OCW2
Address: Base + 0
Interrupt level
Access: Write
000 IR0
0
0
001 IR1
010 IR2
011 IR3
100 IR4
101 IR5
110 IR6
111 IR7
Operational mode
End of Interrupt
001 Non-specific
011 Specific
Automatic Rotation
101 Rotate on non-specific
100 Rotate on automatic (set)
000 Rotate on automatic (reset)
Specific Rotation
111 Rotate on specific
110 Set priority level
No Operation
010 Do not use
Operational Register OCW2