Omron CPM2C Operation Manual page 29

Interrupt Program
Execution
Immediate Refreshing
When an interrupt is generated during execution of the main program, main pro-
gram execution is interrupted immediately and the interrupt program is execut-
ed. The following diagram shows the cyclic operation of the CPM2C when an
interrupt program is executed.
Normally, the results of interrupt program execution are transferred to I/O
memory just after program execution (during I/O refreshing), but IORF(97) can
be used to refresh a specified range of I/O words during execution of the inter-
rupt program. The specified range of I/O words will be refreshed when IORF(97)
is executed.
The normal cycle time is extended by the time required for execution of the inter-
rupt program.
Refer to Section 7 PC Operations and Processing Time in the Programming
Manual (W353) for more details and precautions on the cycle time.
Cycle
time
IORF(97) can be executed in the program to refresh a specified range of I/O
words. The specified I/O words will be refreshed when IORF(97) is executed.
IORF(97) can be used to refresh I/O from the main program or the interrupt pro-
gram.
Overseeing processes
Main program
I/O refreshing
RS-232C port servicing
Peripheral port servicing
Section 1-3
Interrupt generated.
Interrupt program