Chapter 6. Service Request Function306 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C6.18 SVC_REQ 17: Mask/Unmask I/O InterruptUse SVC_REQ 17 to mask or unmask an interrupt from an input/output board. When an interrupt ismasked, the CPU does not execute the corresponding interrupt block when the input transitions andcauses an interrupt.The parameter block is an input parameter block only; it has a length of three words.Address 0 = unmask input1 = mask inputAddress+1 memory typeAddress+2 reference (offset)Memory type is a decimal number that resides in the low byte of word address + 1. It corresponds tothe memory type of the input:70 %I memory in bit mode10 %AI memory12 %AQ memorySuccessful execution occurs unless:▪ Some number other than 0 or 1 is entered as the requested operation.▪ The memory type of the input/output to be masked or unmasked is not %I, %AI or %AQ memory.▪ The I/O board is not a supported input/output module.▪ The reference address specified does not correspond to a valid interrupt trigger reference.▪ The specified channel does not have its interrupt enabled in the configuration.6.18.1 Masking/Unmasking Module InterruptsDuring module configuration, interrupts from a module can be enabled or disabled. If a module'sinterrupt is disabled, it cannot be used to trigger logic execution in the application program and itcannot be unmasked. However, if an interrupt is enabled in the configuration, it can be dynamicallymasked or unmasked by the application program during system operation.The application program can mask and unmask interrupts that are enabled using Service RequestFunction Block #17. To mask or unmask an interrupt from an open VME module, the application logicshould pass VME_INT_ID (17 decimal, 11H) as the memory type and the VME interrupt id as theoffset to SVC_REQ 17.When the interrupt is not masked, the CPU processes the interrupt and schedules the associatedprogram logic for execution. When the interrupt is masked, the CPU processes the interrupt but doesnot schedule the associated program logic for execution.When the CPU transitions from STOP Mode to RUN Mode, the interrupt is unmasked.For additional information on configuring and using VME module interrupts in a PACSystems RX7icontrol system, refer to PACSystems RX7i User's Guide to Integration of VME Modules, GFK-2235.
