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

#### DFXBK

Prolog

Control Block Contents
DFXBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### DFXBK Prolog

     NAME       : HCPFCWDS
     DESCRIPTION: Define Extent Parameter
     DSECT      : DFXBK

#### DFXBK Control Block Content

#### DFXBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      DFXBK          Define Extent Parameter
    0000    0 Bitstring    1 DFXMASK        Mask byte
    0001    1 Bitstring    1 DFXATRB        Global attributes
    0002    2 Signed       2 DFXBSIZE       Block size in bytes
    0004    4 Signed       4 DFXEXTLO (0)   Extent locator for FBA
         The following redefines the DFXEXTLO for ECKD devices
    0004    4 Bitstring    2 DFXCACID       Cache fast write ID
    0006    6 Character    1 *
    0007    7 Bitstring    1 DFXGATBE       Global Attributes Extended
              .... .1..      DFXSTDRZ       X'04' Regular record zero
    0008    8 Bitstring    4 DFXSTART       Beginning of extent
    000C   12 Bitstring    4 DFXEND         End of extent
              11.. ....      DFXECKD        X'C0' Mask to check architecture

#### DFXBK Storage Layout

    *** DFXBK - Define Extent Parameter
    *
    *     +------+------+-------------+-------------+------+------+
    *   0 |:MASK |:ATRB |  DFXBSIZE   |  DFXCACID   |//////|:GATBE|
    *     +------+------+-------------+-------------+------+------+
    *   8 |         DFXSTART          |          DFXEND           |
    *     +---------------------------+---------------------------+
    *  10
    *
    *** DFXBK - Define Extent Parameter

#### DFXBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    DFXATRB        0001
    DFXBSIZE       0002
    DFXCACID       0004
    DFXECKD        000C C0
    DFXEND         000C
    DFXEXTLO       0004
    DFXGATBE       0007
    DFXMASK        0000
    DFXSTART       0008
    DFXSTDRZ       0007 04

This information is based on z/VM V4R3.0. Last updated on 1 May 2002 at 08:41:02 EDT.
Copyright IBM Corporation, 1990, 2002