PAGBK

Prolog  

Control Block Contents  
   PAGBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

PAGBK Prolog

 NAME       : HCPPAGBK
 DESCRIPTION: Page I/O DSECT Block
 DSECT      : PAGBK
 FUNCTION   : PAGBK maps a free storage block that contains
              the IORBK, EXPBK (for single exposures), and
              the Set Paging Parameter CCW or the Define
              Extent Data Area.
 LOCATED BY : EXPIORBK - Field in the exposure block that points
              to the beginning of the block.
 RELOCATION CONSIDERATIONS : None
 NOTES      : To use this dsect the following dsects must also
              be included in the module. HCPIORBK, HCPEXPBK.
              This block contains an IORBK and CCW data.  It must
              be backed below 2-Gig.  (Defaulted in CBITABLE).

PAGBK Control Block Content

PAGBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      PAGBK          Page I/O DSECT Block
             Beginning of the IORBK for this exposure.
0000    0 Dbl-Word     8 PAGIORBK (67)  This area reserved for the IORBK.
0218  536 Dbl-Word     8 PAGEXPBK (25)  This area reserved for the EXPBK.
             The area below is used for the Set Paging CCW data.
02E0  736 Bitstring   32 PAGSPPAR (0)   This area contains the cache CCW
                                        data information.
02E0  736 Bitstring   10 PAGDATA (0)    This is the data area for the Set
                                        Paging Parameter CCW.
02E0  736 Bitstring    1 *
02E1  737 Bitstring    9 PAGDATA1 (0)   Defined for the clear move
                                        instruction.
02E1  737 Bitstring    5 *
02E6  742 Bitstring    4 PAGCCHH        The cylinder/head info.
02EA  746 Bitstring   22 *              Reserved for IBM use
             Redefinition of set paging parameter data area
             for ECKD and FBA paging devices.
02E0  736 Bitstring   32 PAGDXDA        Define extent data area mapped by
                                        DXDA (ECKD) or DFDA (FBA)
          00000300       PAGCKSIZ       *-PAGBK Actual block size in
                                        bytes
          00000060       PAGSIZE        (((*-PAGBK)+7)/8) PAGBK siz in
                                        DWs (leave room for expansion)
          00000300       PAGBSIZE       *-PAGBK Non theoretical PAGBK
                                        size in bytes (leave room for
                                        expansion)

PAGBK Storage Layout

          
*** PAGBK - Page I/O DSECT Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       PAGIORBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 218 |                                                       |
*     =                       PAGEXPBK                        =
*     |                                                       |
*     +------+----------------------------------+-------------+
* 2E0 |//////|//////////////////////////////////|  PAGCCHH-   |
*     +------+------+---------------------------+-------------+
* 2E8 |   -(2E6)    |/////////////////////////////////////////|
*     +-------------+/////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
* 300
*
*** PAGBK - Page I/O DSECT Block
          
*** Overlay for PAGSPPAR in PAGBK
*
*     +-------------------------------------------------------+
* 2E0 |                                                       |
*     =                       PAGDXDA                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 300
*
*** Overlay for PAGSPPAR in PAGBK

PAGBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
PAGBSIZE       02E0 00000300
PAGCCHH        02E6
PAGCKSIZ       02E0 00000300
PAGDATA        02E0
PAGDATA1       02E1
PAGDXDA        02E0
PAGEXPBK       0218
PAGIORBK       0000
PAGSIZE        02E0 00000060
PAGSPPAR       02E0