gtps1m0gSystem Macros

$DISBC-Disconnect A Block from the ECB Virtual Memory

Use this system macro to disconnect a storage block from the entry control block (ECB) virtual memory (EVM). The macro is used by the TPF system for data that should no longer be accessible to the ECB (such as output messages after the ROUTC macro). The TPF system also uses this macro to support macros (such as the CREEC macro) that pass main storage blocks from one ECB to another.

Format




BLOCK=Rn
This required parameter specifies the register containing the 31-bit EVM address of the block to be disconnected. R13 can not be specified for this register. The block must be of a type that can be attached to ECB core block reference words (CBRWs) (128, 381, 1055, or 4095 bytes).

On return, the register contains the 31-bit SVM address of the disconnected block.

SAVREG
The specified volatile registers will be saved by the macro in the stack area or in the registers specified by the WKREG parameter. Up to 3 registers can be specified. Those registers are R0, R1, R2. If this keyword is omitted, none of the 3 registers will be saved. You should not save a volatile register if you expect it to contain an output parameter. The register will be overwritten with its original contents, since the reload is the last thing performed by the macro.

WKREG
The specified symbolic register names are free to be used by the macro to save the volatile registers coded on the SAVREG parameter. Up to 3 registers can be specified, but the standard linkage registers R13 through R2 cannot be used here. This parameter is used in conjunction with the SAVREG parameter to generate efficient code and enhance the performance of the macro. The number of registers specified by WKREG should be less than or equal to the number of registers specified by SAVREG. If this parameter is omitted or not used to its maximum capacity, code optimization is sacrificed.

Entry Requirements

Return Conditions

Programming Considerations

Examples

None.