HCCW | Back to Index page

| Prolog Control Block Contents HCCW DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

HCCW Prolog | Top of page

     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
     RELOCATION CONSIDERATIONS : None

HCCW Control Block Content | Top of page

     HCCW DSECT
    Top of page

    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' CCWDC CHAIN DATA ADDRESS
                                            AND COUNT
              .1.. ....      CCWCC          X'40' CCWCC COMMAND CHAIN
              ..1. ....      CCWSILI        X'20' CCWSILI SUPPRESS INCORRECT
                                            LENGTH
              ...1 ....      CCWSKIP        X'10' CCWSKIP SUPPRESS INBOUND
                                            DATA TRANSFER
              .... 1...      CCWPCIR        X'08' CCWPCIR REQUEST PC
                                            INTERRUPTION
              .... .1..      CCWIDA         X'04' CCWIDA INDIRECT DATA
                                            ADDRESSING
              .... ..11      CCWINVAL       X'03' CCWINVAL I/O UNDEFINED PAIR
                                            OF BITS
              .... ..1.      CCWSUSPN       X'02' CCWSUSPN I/O
                                            SUSPENSION/RESUMPTION The
                                            CCWUNDEF definition is left here
                                            because some code still uses this
                                            field where the CCWMIDA bit is
                                            not applicable.
              .... ...1      CCWUNDEF       X'01' CCWUNDEF I/O UNDEFINED BIT
              .... ...1      CCWMIDA        X'01' CCWMIDA
                                            Modified-CCW-indirect-data-addres
                                            sing
    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 | Top of page

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

HCCW Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    CCWCC          0001 40
    CCWDC          0001 80
    CCWIDA         0001 04
    CCWINVAL       0001 03
    CCWMIDA        0001 01
    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 7.2.0 Last updated on 24 Jun 2020 at 09:28:27 EDT.
Copyright IBM Corporation, 1990, 2020