CICS address space modules

The CICS® address space modules control the handling of requests between this address space and other address spaces. They include several MRO management modules such as DFHCRSP (see DFHCRSP (CICS IRC startup module)) and DFHCRNP (see DFHCRNP (connection manager—CSNC transaction)), and several terminal-control modules (see DFHZCX (CICS terminal control routines)).

These modules provide the CICS address space with a DFHTC-level interface to interregion communication (in the same way as DFHZCP provides a DFHTC-level interface to z/OS® Communications Server). This enables other CICS modules (such as DFHISP) to allocate and execute input/output operations on IRC sessions. The IRC sessions are used for all forms of IRC communication, and the macro-level services available for IRC are broadly the same. Thus DFHISP works for both IRC and intersystem communication (ISC) function shipping.

The functions of each module are as follows: