Use the IHADCBE mapping macro to identify DCB extension field names symbolically. If you load a base register with a DCBE address, you can refer to any field symbolically. You can code the IHADCBE macro once to describe all DCBEs.

The IHADCBE macro generates a dummy control section (DSECT) named DCBE. For the symbols generated see z/OS DFSMS Macro Instructions for Data Sets.

All address fields in the DCBE are 4 bytes. All undefined addresses are set to 0.