Use this system macro to halt a current active input/output (I/O)
request for a symbolic device address (SDA).
Format
- label
- A symbolic name may be assigned to the macro statement.
- SDA=label|(Rx)
- Is either a label of a halfword field containing an SDA or a register that
contains an SDA in bytes 2-3 and zeros in bytes 0-1.
Entry Requirements
- The TPF system must be disabled for interrupts.
- The TPF system must be running with PSW Key 0.
Return Conditions
- Control is returned to the next sequential instruction (NSI) with the
condition code set as follows.
- Condition Code
- Meaning
- 0
- No active request to stop.
- 2
- Halt in progress.
- 3
- An SDA that is not valid.
- The contents of all registers are preserved across this macro call.
Programming Considerations
- This macro can be run on the main I-stream only.
- This macro is for use in the control program (CP) only.
Examples
None.