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
 RELOCATION CONSIDERATIONS : None

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' 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

          
*** 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
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