Use this system macro to start a normal input/output (I/O)
operation to a specific symbolic device address (SDA).
Format
- label
- A symbolic name can be assigned to the macro statement.
- DOR=label|(Rx)
- This is either a label assigned to an area defined by the device operation
request block (DCTDOR) DSECT or a register containing the address of a
DOR.
Entry Requirements
- The TPF system must be disabled for interrupts.
- The TPF system must be running with PSW Key 0.
- The DCTDOR DSECT completed with:
SDA address
Protect key for data area
CCW format flag
Logical path mask
Channel program address.
- And optionally set:
Lost interrupt timeout value
Request-unique parameter.
Return Conditions
- Control is returned to the next sequential instruction (NSI).
- The condition code will be set as follows.
- Condition Code
- Meaning
- 0
- The request was accepted.
- 2
- A request was already active.
- 3
- The SDA is not valid.
- The contents of all registers are preserved across this macro call.
Programming Considerations
This macro is for use in the control program (CP) only.
Examples
None.