IBM: S1CCW

Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

S1CCW

Prolog

Control Block Contents

S1CCW DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

S1CCW Prolog

 NAME       : HCPS1CCW
 DESCRIPTION: SPOOLing Format 1 Channel Control
              Word Pairs
 DSECT      : S1CCW
 FUNCTION   : Provide symbolic references for the fields of
              the format 1 (XA) CCW pairs used by spooling
              in the spool files.
 LOCATED BY : N/A
 CREATED BY : N/A
 DELETED BY : N/A

S1CCW Control Block Content


S1CCW DSECT
Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      S1CCW          SPOOLing Format 1 Channel Control
0000    0 Unknown      ? S1CCWPAR (0)   FORMAT 1 (System 370/XA CCW Pair)
0000    0 Signed       4 S1CCWWD0 (0)   First word of the CCW pair
0000    0 Bitstring    1 S1CCWCMD       CCW command code
0001    1 Bitstring    1 S1CCWFLG       Control of CCW flags
          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 S1CCWCNT       Count for I/O
0004    4 Address      4 S1CCWADR       CCW address (31-BIT)
0008    8 Signed       4 S1CCWWD2 (0)   Third word of CCW pair
0008    8 Bitstring    1 S1CCWTCC       CCW command code
0009    9 Bitstring    1 S1CCWTCU (3)   No TIC flags or count For a
                                        format 1 CCW, this unused field
                                        of the TIC must be zero.
000C   12 Address      4 S1CCWTCA       CCW address (31-BIT)
0010   16 Dbl-Word     8 S1CCWDAT (0)   Start of variable length data
          00000010       S1CCWLEN       (*-S1CCW) Length of a FORMAT 1
                                        CCW pair in bytes
     S1CCWOL is a 2 byte field used to contain the original data length for
     CCWs which have had blanks compressed from the data. This field is
     nonexistent for CCWs in which compression does not occur. The exception
     is TAG processing which always has the original data length appended to
     the end of the tag data field. S1CCWOL is located following the data.
     However, direct addressability cannot be achieved due to the preceding
     variable length data field.
0010   16 Bitstring    2 S1CCWOL        Value of the original data length

S1CCW Storage Layout

*** S1CCW - SPOOLing Format 1 Channel Control
*
*     +------+------+-------------+---------------------------+
*   0 |:CWCMD|:CWFLG|  S1CCWCNT   |         S1CCWADR          |
*     +------+------+-------------+---------------------------+
*   8 |:CWTCC|     S1CCWTCU       |         S1CCWTCA          |
*     +------+------+-------------+---------------------------+
*  10 |  S1CCWOL    | 12
*     +-------------+
*
*** S1CCW - SPOOLing Format 1 Channel Control