CHRBK | Back to Index page

| Prolog Control Block Contents CHRBK 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.

CHRBK Prolog | Top of page

     NAME       : HCPCHRBK
     DESCRIPTION: DEVICE / SUBCHANNEL INDEX STRUCTURE
     DSECT      : CHRBK
     FUNCTION   : THE DEVICE / SUBCHANNEL RADIX TREE BLOCK IS USED
                  TO REPRESENT THE DEVICE BLOCK INDEX STRUCTURE
     LOCATED BY : HCPRIOIX and HCPRIOIA contain the radix tree
                  for the real device numbers (in the default
                  subchannel set and the alternate subchannel set
                  respectively) which addresses the CHRBK for the
                  first digit of the device number.
     CREATED BY : CHRBK'S ARE DYNAMICALLY CREATED BY CALLING
                  HCPFREE
     DELETED BY : CHRBK'S ARE DELETED BY CALLING HCPFRET
     RELOCATION CONSIDERATIONS : None
     COMMENTS   : NONE

CHRBK Control Block Content | Top of page

     CHRBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      CHRBK          DEVICE / SUBCHANNEL INDEX STRUCTURE
    0000    0 Signed       4 CHRINDX0       INDEX FOR DIGIT 0 MOD 16
    0004    4 Signed       4 CHRINDX1       INDEX FOR DIGIT 1 MOD 16
    0008    8 Signed       4 CHRINDX2       INDEX FOR DIGIT 2 MOD 16
    000C   12 Signed       4 CHRINDX3       INDEX FOR DIGIT 3 MOD 16
    0010   16 Signed       4 CHRINDX4       INDEX FOR DIGIT 4 MOD 16
    0014   20 Signed       4 CHRINDX5       INDEX FOR DIGIT 5 MOD 16
    0018   24 Signed       4 CHRINDX6       INDEX FOR DIGIT 6 MOD 16
    001C   28 Signed       4 CHRINDX7       INDEX FOR DIGIT 7 MOD 16
    0020   32 Signed       4 CHRINDX8       INDEX FOR DIGIT 8 MOD 16
    0024   36 Signed       4 CHRINDX9       INDEX FOR DIGIT 9 MOD 16
    0028   40 Signed       4 CHRINDXA       INDEX FOR DIGIT A MOD 16
    002C   44 Signed       4 CHRINDXB       INDEX FOR DIGIT B MOD 16
    0030   48 Signed       4 CHRINDXC       INDEX FOR DIGIT C MOD 16
    0034   52 Signed       4 CHRINDXD       INDEX FOR DIGIT D MOD 16
    0038   56 Signed       4 CHRINDXE       INDEX FOR DIGIT E MOD 16
    003C   60 Signed       4 CHRINDXF       INDEX FOR DIGIT F MOD 16
              ..11 11..      CHROMASK       CHRINDXF-CHRINDX0 CHROMASK MASK
                                            TO ISOLATE THE OFFSET TO
                                            INDX0-INDXF
              00000008       CHRSIZE        (*-CHRBK+7)/8 SIZE OF BLOCK IN
                                            DBW'S

CHRBK Storage Layout | Top of page

    *** CHRBK - DEVICE / SUBCHANNEL INDEX STRUCTURE
    *
    *     +---------------------------+---------------------------+
    *   0 |         CHRINDX0          |         CHRINDX1          |
    *     +---------------------------+---------------------------+
    *   8 |         CHRINDX2          |         CHRINDX3          |
    *     +---------------------------+---------------------------+
    *  10 |         CHRINDX4          |         CHRINDX5          |
    *     +---------------------------+---------------------------+
    *  18 |         CHRINDX6          |         CHRINDX7          |
    *     +---------------------------+---------------------------+
    *  20 |         CHRINDX8          |         CHRINDX9          |
    *     +---------------------------+---------------------------+
    *  28 |         CHRINDXA          |         CHRINDXB          |
    *     +---------------------------+---------------------------+
    *  30 |         CHRINDXC          |         CHRINDXD          |
    *     +---------------------------+---------------------------+
    *  38 |         CHRINDXE          |         CHRINDXF          |
    *     +---------------------------+---------------------------+
    *  40
    *
    *** CHRBK - DEVICE / SUBCHANNEL INDEX STRUCTURE

CHRBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    CHRINDXA       0028
    CHRINDXB       002C
    CHRINDXC       0030
    CHRINDXD       0034
    CHRINDXE       0038
    CHRINDXF       003C
    CHRINDX0       0000
    CHRINDX1       0004
    CHRINDX2       0008
    CHRINDX3       000C
    CHRINDX4       0010
    CHRINDX5       0014
    CHRINDX6       0018
    CHRINDX7       001C
    CHRINDX8       0020
    CHRINDX9       0024
    CHROMASK       003C 3C
    CHRSIZE        003C 00000008

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:27:18 EDT.
Copyright IBM Corporation, 1990, 2020