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

#### LEDA

Prolog

Control Block Contents
LEDA DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### LEDA Prolog

     Name       : HCPLEDA
     Description: Locate Record Extended data area
     DSECT      : LEDA
     Function   : Maps the contents of the Locate Record
                  Extended data area.
     Located by :
                  HCCWADDR - The Locate Record Extended CCW data
                  address field contains the address of
                  the locate record extended data area.
     Created by :
                  Storage for this control block cannot be
                  specifically allocated/deallocated using
                  HCPGETST/HCPRELST.
                  Track cache manager -
                  Data area is part of a larger free storage
                  area used to build ECKD channel programs
                  which is allocated in modules HCPFMU/HCPFMP.
     Deleted by :
                  Storage for this control block cannot be
                  specifically allocated/deallocated using
                  HCPGETST/HCPRELST.
                  Track cache manager -
                  Data area is part of a larger free storage
                  area used to build ECKD channel programs
                  which is deallocated in modules HCPFMU/HCPFMP.
     Serialized :
                  Track cache manager -
                  TCMTSLK  - Track cache lock
     Comments   :
                  Track cache manager -
                  None

#### LEDA Control Block Content

#### LEDA DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      LEDA           Locate Record Extended data area
    0000    0 Bitstring   16 LEDAREA (0)    Locate Record Extended data area
                 Byte 0 (Operation byte)
                 Although defined as BITs, the contents of the
                 operation byte are, architecturally, multiple
                 codes.
    0000    0 Bitstring    1 LEDOP          Operation byte
              11.. ....      LEDOR          X'C0' Operation byte, bits 0 and
                                            1 ------- Codes for use with
                                            LEDOR
              .... ....      LEDORCA        X'00' Orient on count area
              .1.. ....      LEDORHA        X'40' Orient on home address
              1... ....      LEDORDA        X'80' Orient on data area
              11.. ....      LEDORIX        X'C0' Orient on index -------
              ..11 1111      LEDOOC         X'3F' Operation byte, bits 2
                                            through 7 ------- Codes for use
                                            with LEDOOC
              .... ...1      LEDOCWD        X'01' Write data
              .... ..11      LEDOCFW        X'03' Format write
              .... .11.      LEDOCRD        X'06' Read data
              .... 1.11      LEDOCWT        X'0B' Write track
              .... 11..      LEDOCRT        X'0C' Read tracks
              ...1 .11.      LEDOCR         X'16' Read
              ..11 1111      LEDOCX         X'3F' Extended Op Code -------
                 Byte 1 (Auxiliary byte)
    0001    1 Bitstring    1 LEDAUX         Auxiliary byte
              1... ....      LEDAVTLF       X'80' Validate transfer length
                                            factor
              .... ...1      LEDARCS        X'01' Read count suffix
                 Byte 2 (Zeros)
    0002    2 Bitstring    1 LEDZEROS       Must be zeros
                 Byte 3 (Count)
    0003    3 Bitstring    1 LEDCOUNT       Count
                 Bytes 4 through 7 (Seek address)
    0004    4 Bitstring    4 LEDSEEK (0)    Seek address (CCHH)
    0004    4 Bitstring    2 LEDSCC         CC of CCHH
    0006    6 Bitstring    2 LEDSHH         HH of CCHH
                 Bytes 8 through 12 (Search argument)
    0008    8 Bitstring    5 LEDSRCH (0)    Search argument (CCHHR)
    0008    8 Bitstring    2 LEDRCC         CC of CCHHR
    000A   10 Bitstring    2 LEDRHH         HH of CCHHR
    000C   12 Bitstring    1 LEDRR          R of CCHHR
                 Byte 13 (Sector number)
    000D   13 Bitstring    1 LEDSECT        Sector number
              1111 1111      LEDNOSCT       X'FF' Sector orientation not
                                            performed
                 Bytes 14 and 15 (Transfer length factor)
    000E   14 Bitstring    2 LEDTLF         Transfer length factor
                 Byte 16  (Reserved)
    0010   16 Bitstring    1 LEDRES         Reserved for IBM use
                 Byte 17  (Extended Operation)
    0011   17 Bitstring    1 LEDEOP         Extended Operation
              .... ....      LEDOTHOP       X'00' Use operation code in byte
                                            0
              .... 1..1      LEDWRANY       X'09' Write Any
              .... 1.1.      LEDRDANY       X'0A' Read Any
              .... 111.      LEDRDTKS       X'0E' Read Trackset
              ...1 ....      LEDPRETS       X'10' Prestage Trackset
              ...1 ...1      LEDWRTKS       X'11' Write Trackset
              ...1 ..11      LEDUWRTK       X'13' Update Write Trackset
                 Bytes 18-19 (Extended Parameter Length)
    0012   18 Bitstring    2 LEDEPLEN       Extended Parameter Length
                 Bytes 20-21 (Extended Parameter)
    0014   20 Bitstring    1 LEDEPRM1       Extended Parameter byte 1
    0015   21 Bitstring    1 LEDEPRM2       Extended Parameter byte 2
                 Length equates
              00000016       LEDBSIZE       *-LEDAREA Size of LEDA in bytes
              00000003       LEDSIZE        ((*-LEDAREA)+7)/8 Size of LEDA in
                                            DWs

#### LEDA Storage Layout

    *** LEDA - Locate Record Extended data area
    *
    *     +------+------+------+------+-------------+-------------+
    *   0 |LEDOP |LEDAUX|:ZEROS|:COUNT|   LEDSCC    |   LEDSHH    |
    *     +------+------+------+------+------+------+-------------+
    *   8 |   LEDRCC    |   LEDRHH    |LEDRR |:SECT |   LEDTLF    |
    *     +------+------+-------------+------+------+-------------+
    *  10 |LEDRES|LEDEOP|  LEDEPLEN   |:EPRM1|:EPRM2| 16
    *     +------+------+-------------+------+------+
    *
    *** LEDA - Locate Record Extended data area

#### LEDA Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    LEDARCS        0001 01
    LEDAREA        0000
    LEDAUX         0001
    LEDAVTLF       0001 80
    LEDBSIZE       0015 00000016
    LEDCOUNT       0003
    LEDEOP         0011
    LEDEPLEN       0012
    LEDEPRM1       0014
    LEDEPRM2       0015
    LEDNOSCT       000D FF
    LEDOCFW        0000 03
    LEDOCR         0000 16
    LEDOCRD        0000 06
    LEDOCRT        0000 0C
    LEDOCWD        0000 01
    LEDOCWT        0000 0B
    LEDOCX         0000 3F
    LEDOOC         0000 3F
    LEDOP          0000
    LEDOR          0000 C0
    LEDORCA        0000 00
    LEDORDA        0000 80
    LEDORHA        0000 40
    LEDORIX        0000 C0
    LEDOTHOP       0011 00
    LEDPRETS       0011 10
    LEDRCC         0008
    LEDRDANY       0011 0A
    LEDRDTKS       0011 0E
    LEDRES         0010
    LEDRHH         000A
    LEDRR          000C
    LEDSCC         0004
    LEDSECT        000D
    LEDSEEK        0004
    LEDSHH         0006
    LEDSIZE        0015 00000003
    LEDSRCH        0008
    LEDTLF         000E
    LEDUWRTK       0011 13
    LEDWRANY       0011 09
    LEDWRTKS       0011 11
    LEDZEROS       0002

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 17:00:48 EDT.
Copyright IBM Corporation, 1990, 2005