The EXCPVR interface supports format 0 CCWs. Format 0 CCWs support only 24-bit addresses. All CCWs and IDAWs used with EXCPVR must reside in virtual or central storage below 16 megabytes. The largest virtual or central storage address you can specify directly in your channel program is 16 megabytes minus one. However, using IDAWs (indirect data address words) you can specify any central storage address and therefore you can perform I/O to any location in real or virtual storage. EXCPVR channel programs must use IDAWs to specify buffer addresses above 16 megabytes in central storage.
You must assume that buffers obtained by data management access methods have real storage addresses above 16 megabytes.
For more EXCPVR information, see z/OS DFSMSdfp Advanced Services.