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

#### HCCW

Prolog

Control Block Contents
HCCW DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### HCCW Prolog

     NAME       : HCPHCCW
     DESCRIPTION: HOST CHANNEL CONTROL WORD
     DSECT      : HCCW
     FUNCTION   : PROVIDE SYMOLIC REFERENCES FOR THE FIELDS OF THE FORMAT
                  ONE CCWS USED BY CP
     LOCATED BY : N/A
     CREATED BY : N/A
     DELETED BY : N/A

#### HCCW Control Block Content

#### HCCW DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      HCCW           HOST CHANNEL CONTROL WORD
    0000    0 Dbl-Word     8 HCCW1 (0)      AN ENTIRE FORMAT 1 CCW
    0000    0 Signed       4 HCCWCFCT (0)   Format 1 CCW first word - cmd,
                                            flag, and count
    0000    0 Bitstring    1 HCCWCMND       CCW COMMAND CODE
    0001    1 Bitstring    1 HCCWFLAG       CCW FLAG BITS
              1... ....      CCWDC          X'80' CHAIN DATA ADDRESS AND
                                            COUNT
              .1.. ....      CCWCC          X'40' COMMAND CHAIN
              ..1. ....      CCWSILI        X'20' SUPPRESS INCORRECT LENGTH
              ...1 ....      CCWSKIP        X'10' SUPPRESS INBOUND DATA
                                            TRANSFER
              .... 1...      CCWPCIR        X'08' REQUEST PC INTERRUPTION
              .... .1..      CCWIDA         X'04' INDIRECT DATA ADDRESSING
              .... ..11      CCWINVAL       X'03' I/O UNDEFINED PAIR OF BITS
              .... ..1.      CCWSUSPN       X'02' I/O SUSPENSION/RESUMPTION
              .... ...1      CCWUNDEF       X'01' I/O UNDEFINED BIT
    0002    2 Signed       2 HCCWCNT        CCW DATA COUNT
    0004    4 Address      4 HCCWADDR       CCW DATA ADDRESS
              00000007       HCCWADRX       *-1 CCW FINAL BYTE OF ADDRESS
    0008    8 Dbl-Word     8 HCCWNEXT (0)   CCW FOLLOWING CURRENT CCW
              0000000F       HCCWIS         B'1111' ICM/STCM MASK FOR 31 BIT
                                            ADDRESS
              00000004       HCCWMC         04 MVC/CLC LENGTH FOR 31 BIT
                                            ADDRESS
              00000080       HCCWIDAL       B'10000000' IDAL INVALID BIT MASK
              00000008       HCCWLEN        8 LENGTH OF A SINGLE CCW (8
                                            BYTES)

#### HCCW Storage Layout

    *** HCCW - HOST CHANNEL CONTROL WORD
    *
    *     +------+------+-------------+---------------------------+
    *   0 |:WCMND|:WFLAG|  HCCWCNT    |         HCCWADDR          |
    *     +------+------+-------------+---------------------------+
    *
    *** HCCW - HOST CHANNEL CONTROL WORD

#### HCCW Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    CCWCC          0001 40
    CCWDC          0001 80
    CCWIDA         0001 04
    CCWINVAL       0001 03
    CCWPCIR        0001 08
    CCWSILI        0001 20
    CCWSKIP        0001 10
    CCWSUSPN       0001 02
    CCWUNDEF       0001 01
    HCCWADDR       0004
    HCCWADRX       0004 00000007
    HCCWCFCT       0000
    HCCWCMND       0000
    HCCWCNT        0002
    HCCWFLAG       0001
    HCCWIDAL       0008 00000080
    HCCWIS         0008 0000000F
    HCCWLEN        0008 00000008
    HCCWMC         0008 00000004
    HCCWNEXT       0008
    HCCW1          0000

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 16:58:17 EDT.
Copyright IBM Corporation, 1990, 2005