GE PACSystems RX7i

Chapter 6. Service Request Function
GFK-2950C February 2018 321
6.23 SVC_REQ 22: Mask/Unmask Timed Interrupts
Use SVC_REQ 22 to mask or unmask timed interrupts and to read the current mask. When the
interrupts are masked, the CPU does not execute any timed interrupt block timed program that is
associated with a timed interrupt. Timed interrupts are masked/unmasked as a group. They cannot
be individually masked or unmasked.
Successful execution occurs unless some number other than 0 or 1 is entered as the requested
operation or mask value.
The parameter block is an input and output parameter block.
To determine the current mask, use this format:
Address
0 = Read interrupt mask
The CPU returns this format:
Address
0 = Read interrupt mask
Address+1
0 = Timed interrupts are
unmasked
1 = Timed interrupts are masked
To change the current mask, use this format:
Address
1 = Mask/unmask interrupts
Address+1
0 = Unmask timed interrupts
1 = Mask timed interrupts
SVC_REQ 22 Example
When input %I00055 transitions on, timed interrupts are masked.