LRDA

Prolog  

Control Block Contents  
   LRDA DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

LRDA Prolog

 Name       : HCPLRDA
 Description: Locate Record data area
 DSECT      : LRDA
 Function   : Maps the contents of the Locate Record data
              area.
 Located by :
              HCCWADDR - The Locate Record CCW data address field
              contains the address of the locate
              record data area.
 Created by :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Paging I/O manager -
              The data area resides in the HCPPIOBK which
              is allocated by HCPRDA.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build ECKD channel programs
              which is allocated in modules HCPFTU/HCPFTP.
 Deleted by :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Paging I/O manager -
              The data area resides in the HCPPIOBK which
              is allocated by HCPRDD.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build ECKD channel programs
              which is deallocated in modules HCPFTU/HCPFTP.
 Serialized :
              Paging I/O manager -
              EXPLCKFG - The paging I/O manager uses the exposure
              block lock to serialize this data area.
              Track cache manager -
              TCMTSLK  - Track cache lock
 Comments   :
              Paging I/O manager -
              The Locate Record data area resides in the
              HCPPIOBK. Each Locate Record CCW address field
              contains the address of the Locate Record data
              area within that PIOBK.
              Track cache manager -
              None

LRDA Control Block Content

LRDA DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      LRDA           Locate Record data area
0000    0 Bitstring   16 LRDAREA (0)    Locate record data area
     Byte 0 (Operation byte)
     Although defined as BITs, the contents of the operation byte are,
     architecturally, multiple codes.
0000    0 Bitstring    1 LRDOP          Operation byte
          11.. ....      LRDOR          X'C0' Operation byte, bits 0 and
                                        1 ------- Codes for use with
                                        LRDOR
          .... ....      LRDORCA        X'00' Orient on count area
          .1.. ....      LRDORHA        X'40' Orient on home address
          1... ....      LRDORDA        X'80' Orient on data area
          11.. ....      LRDORIX        X'C0' Orient on index -------
          ..11 1111      LRDOOC         X'3F' Operation byte, bits 2
                                        through 7 ------- Codes for use
                                        with LRDOOC
          .... ....      LRDOCOR        X'00' Orient
          .... ...1      LRDOCWD        X'01' Write data
          .... ..11      LRDOCFW        X'03' Format write
          .... .11.      LRDOCRD        X'06' Read data
          .... 1.11      LRDOCWT        X'0B' Write track
          .... 11..      LRDOCRT        X'0C' Read tracks
          ...1 .11.      LRDOCR         X'16' Read -------
     Byte 1 (Auxiliary byte)
0001    1 Bitstring    1 LRDAUX         Auxiliary byte
          1... ....      LRDAVTLF       X'80' Validate transfer length
                                        factor
          .... ...1      LRDARCS        X'01' Read count suffix
     Byte 2 (Zeros)
0002    2 Bitstring    1 LRDZEROS       Must be zeros
     Byte 3 (Record count)
0003    3 Bitstring    1 LRDRECCT       Record count
     Bytes 4 through 7 (Seek address)
0004    4 Bitstring    4 LRDSEEK (0)    Seek address (CCHH)
0004    4 Bitstring    2 LRDSCC         CC of CCHH
0006    6 Bitstring    2 LRDSHH         HH of CCHH
     Bytes 8 through 12 (Search argument)
0008    8 Bitstring    5 LRDSRCH (0)    Search argument (CCHHR)
0008    8 Bitstring    2 LRDRCC         CC of CCHHR
000A   10 Bitstring    2 LRDRHH         HH of CCHHR
000C   12 Bitstring    1 LRDRR          R of CCHHR
     Byte 13 (Sector number)
000D   13 Bitstring    1 LRDSECT        Sector number
     Bytes 14 and 15 (Transfer length factor)
000E   14 Bitstring    2 LRDTLF         Transfer length factor
     Length equates
          00000010       LRDBSIZE       *-LRDAREA Size of LRDA in bytes
          00000002       LRDSIZE        ((*-LRDAREA)+7)/8 Size of LRDA in
                                        DWs

LRDA Storage Layout

          
*** LRDA - Locate Record data area
*
*     +------+------+------+------+-------------+-------------+
*   0 |LRDOP |LRDAUX|:ZEROS|:RECCT|   LRDSCC    |   LRDSHH    |
*     +------+------+------+------+------+------+-------------+
*   8 |   LRDRCC    |   LRDRHH    |LRDRR |:SECT |   LRDTLF    |
*     +-------------+-------------+------+------+-------------+
*  10
*
*** LRDA - Locate Record data area

LRDA Cross Reference

Symbol         Dspl Value
-------------- ---- -----
LRDARCS        0001 01
LRDAREA        0000
LRDAUX         0001
LRDAVTLF       0001 80
LRDBSIZE       000E 00000010
LRDOCFW        0000 03
LRDOCOR        0000 00
LRDOCR         0000 16
LRDOCRD        0000 06
LRDOCRT        0000 0C
LRDOCWD        0000 01
LRDOCWT        0000 0B
LRDOOC         0000 3F
LRDOP          0000
LRDOR          0000 C0
LRDORCA        0000 00
LRDORDA        0000 80
LRDORHA        0000 40
LRDORIX        0000 C0
LRDRCC         0008
LRDRECCT       0003
LRDRHH         000A
LRDRR          000C
LRDSCC         0004
LRDSECT        000D
LRDSEEK        0004
LRDSHH         0006
LRDSIZE        000E 00000002
LRDSRCH        0008
LRDTLF         000E
LRDZEROS       0002