Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### CPTBK

Prolog

Control Block Contents
CPTBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### CPTBK Prolog

     NAME       : HCPCPTBK
     DESCRIPTION: Channel program initialization block
     DSECT      : CPTBK
     FUNCTION   : To map the common channel program init. block
     LOCATED BY :
                  RDCCPTA field in the HCPRDC Block.
     CREATED BY : CPTBK'S are static and are created by invocations
                  of the HCPCPTBL macro within module HCPCPG.
     DELETED BY : CPTBK'S are not deleted.
     SERIALIZED : NONE.

#### CPTBK Control Block Content

#### CPTBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      CPTBK          Channel program initialization
                                            block
    0000    0 Dbl-Word     8 * (0)          Start of channel prog init. block
                                            Read Label
    0000    0 Signed       4 RDLBS          Read Label CP Size
    0004    4 Address      4 RDLBA          Read Label CP Entry Point Read
                                            Alloc Map
    0008    8 Signed       4 RALOCS         Read Alloc CP Size
    000C   12 Address      4 RALOCA         Read Alloc CP Entry Point Write
                                            Label
    0010   16 Signed       4 WRTLBS         Write Label CP Size
    0014   20 Address      4 WRTLBA         Write Label CP Entry Point Write
                                            Alloc Map
    0018   24 Signed       4 WALOCS         Write Alloc CP Size
    001C   28 Address      4 WALOCA         Write Alloc CP Entry Point Erase
                                            Extent
    0020   32 Signed       4 EREXTS         Erase Extent CP Size
    0024   36 Address      4 EREXTA         Erase Extent CP Entry Point
                                            Unload Buffer
    0028   40 Signed       4 UNLODS         Unload Buffer CP Size
    002C   44 Address      4 UNLODA         Unload Buffer CP Entry Point
                                            Sense Id
    0030   48 Signed       4 SNSIDS         Sense ID CP Size
    0034   52 Address      4 SNSIDA         Sense ID CP Entry Point Perform
                                            Subsystem Function
    0038   56 Signed       4 PSFS           PSF CP Size
    003C   60 Address      4 PSFA           PSF CP Entry Point
    0040   64 Bitstring    1 CPARCH         Device Arch
              1... ....      CPFBA          X'80' Device Arch is DASD/FBA
              .1.. ....      CPCKD          X'40' Device Arch is DASD/CKD
              ..1. ....      CPECKD         X'20' Device Arch is DASD/ECKD
              ...1 ....      CPCKDE         X'10' Device Arch is DASD/CKD-E
              .... 1...      CPTAPE         X'08' Device Arch is TAPE
    0041   65 Bitstring    3 *              Reserved
              00000044       CPBTSZ         (*-CPTBK) Number of bytes
              00000009       CPTSIZE        (*-CPTBK+7)/8 Number of
                                            doublewords

#### CPTBK Storage Layout

    *** CPTBK - Channel program initialization block
    *
    *     +---------------------------+---------------------------+
    *   0 |          RDLBS            |          RDLBA            |
    *     +---------------------------+---------------------------+
    *   8 |          RALOCS           |          RALOCA           |
    *     +---------------------------+---------------------------+
    *  10 |          WRTLBS           |          WRTLBA           |
    *     +---------------------------+---------------------------+
    *  18 |          WALOCS           |          WALOCA           |
    *     +---------------------------+---------------------------+
    *  20 |          EREXTS           |          EREXTA           |
    *     +---------------------------+---------------------------+
    *  28 |          UNLODS           |          UNLODA           |
    *     +---------------------------+---------------------------+
    *  30 |          SNSIDS           |          SNSIDA           |
    *     +---------------------------+---------------------------+
    *  38 |           PSFS            |           PSFA            |
    *     +------+--------------------+---------------------------+
    *  40 |CPARCH|////////////////////| 44
    *     +------+--------------------+
    *
    *** CPTBK - Channel program initialization block

#### CPTBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    CPARCH         0040
    CPBTSZ         0041 00000044
    CPCKD          0040 40
    CPCKDE         0040 10
    CPECKD         0040 20
    CPFBA          0040 80
    CPTAPE         0040 08
    CPTSIZE        0041 00000009
    EREXTA         0024
    EREXTS         0020
    PSFA           003C
    PSFS           0038
    RALOCA         000C
    RALOCS         0008
    RDLBA          0004
    RDLBS          0000
    SNSIDA         0034
    SNSIDS         0030
    UNLODA         002C
    UNLODS         0028
    WALOCA         001C
    WALOCS         0018
    WRTLBA         0014
    WRTLBS         0010

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 16:46:14 EDT.
Copyright IBM Corporation, 1990, 2005