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 V5R3.0. Last updated on 25 Jun 2007 at 16:11:38 EDT.
Copyright IBM Corporation, 1990, 2007