Omron CPM1 - PROGRAMING MANUAL 02-2001 Programming Manual page 56

CPM2A/CPM2C Interrupt Functions
Reading Current Mask Status
This function is used to read the current mask status for input numbers 00003 to
00006 (interrupt inputs 0 to 3).
(@)INT(89)
Masking or Unmasking All Interrupts
This function is used to mask or unmask all interrupt processing, including inter-
rupt inputs (interrupt input mode and counter mode), interval timer interrupts,
and high-speed counters. Masked inputs are recorded, but ignored.
Masking All Interrupts
(@)INT(89)
Unmasking All Interrupts
(@)INT(89)
The masking or unmasking all interrupts cannot be executed within an interrupt
subroutine.
If causes for interrupts occur while all interrupts are masked, the causes will be
recorded for each interrupt but the interrupt processing will not be executed.
When "unmask all interrupts" is executed, the processing will then be carried out
according to the interrupt mask status at that point in time.
Interrupt masks cannot be cleared simply by executing "unmask all interrupts."
Executing "unmask all interrupts" merely restores the status that was in effect
prior to the execution of "mask all interrupts."
Note INT(89) must be executed in order, with "mask all interrupts" followed by "un-
mask all interrupts."
Interrupt control designation (002: Read current mask status)
002
000 Fixed at 000.
Control data word
C
2
Specifies/stores 0.
Specifies input 00006 (interrupt input 3).
Specifies input 00005 (interrupt input 2).
Specifies input 00004 (interrupt input 1).
Specifies input 00003 (interrupt input 0).
0: Mask is cleared (interrupt inputs permitted).
1: Mask is set (interrupt inputs prohibited).
Interrupt control designation (100: Mask all interrupts)
100
Fixed at 000.
000
Fixed at 000.
000
Interrupt control designation (200: Unmask all interrupts)
200
Fixed at 000.
000
Fixed at 000.
000
Section 2-1
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