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

#### ASCE

Prolog

Control Block Contents
ASCE DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### ASCE Prolog

     Name       : HCPASCE
     Description: Address-Space-Control Element
     DSECT      : ASCE
     Function   : This DSECT maps a z/Arch address-space-control
                  element.  The format of an address-space-control
                  element is architected, and described in the
                  Principles of Operation.
     Located by : CR1      is the ASCE for the primary address space.
                  CR7      is the ASCE for the secondary address space.
                  CR13     is the ASCE for the home address space.
                  ASTASCE  in an ASTE.
                  VMDPASCE is the ASCE for a virtual CPU's current
                  primary address space.
                  PFXSXASC is the ASCE for the system-execution space.
     Created by : HCPASMCR when an address space is created.
                  HCPSSMCR when the system-execution address space is
                  created.
                  HCPFMUSG when the full track cache address space
                  is created.
                  HCPHDTMA when an address space is expanded.
                  HCPHDTNL when an address space is compressed.
     Deleted by : HCPASMDS when the address space is destroyed.

#### ASCE Control Block Content

#### ASCE DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      ASCE           Address-Space-Control Element
          ASCE - 8 bytes, 64 bits
    0000    0 Dbl-Word     8 ASCEALL (0)    Entire ASCE
          64-bit mask  X'FFFFFFFFFFFFF000'  Isolate STO, RTO or RSTO
              00000AF0       ASCEMSK        PFXGPFRA 64-bit mask in PFXPG
              00FFFFFF       ASCETOMH       X'FFFFFFFF' High word of mask
                                            value
              00000AF4       ASCEMSKL       PFXGPFRA+4,4 Low word of mask in
                                            PFXPG
              00FFF000       ASCETOML       X'FFFFF000' Low word of mask
                                            value
          The next four masks are also used by the STD, RTD and RSD.
          64-bit mask  X'0000000000000200'
          32-bit high  X'00000000'
              00000200       ASCEGSM        X'00000200' Isolate
                                            subspace-group control bit
          64-bit mask  X'0000000000000100'
          32-bit high  X'00000000'
              00000100       ASCEPSM        X'00000100' Isolate private-space
                                            control bit
          64-bit mask  X'0000000000000080'
          32-bit high  X'00000000'
              1... ....      ASCESSM        X'00000080' Isolate
                                            storage-alteration- event control
                                            bit
          64-bit mask  X'0000000000000040'
          32-bit high  X'00000000'
              .1.. ....      ASCEXSM        X'00000040' Isolate
                                            space-switch-event control bit
          64-bit mask  X'0000000000000020'
          32-bit high  X'00000000'
              ..1. ....      ASCERBM        X'00000020' Isolate real-space
                                            control bit - R=0: ASCE is an RTD
                                            or STD - R=1: ASCE is an RSD
          64-bit mask  X'000000000000000C'
          32-bit high  X'00000000'
              .... 11..      ASCEDTMK       X'0000000C' Isolate designation
                                            type bits
              00000002       ASCEDTSHF      2 Bits DT is offset from right
                                            edge of ASCE
          64-bit mask  X'0000000000000003'
          32-bit high  X'00000000'
              .... ..11      ASCETLMK       X'00000003' Isolate table length
                                            bits
              0000000C       ASCETLBYT      12 Bits to shift (TL+1) to get
                                            number of bytes in table
    0000    0 Signed       4 ASCEW0 (0)     ASCE Word 0
    0000    0 Bitstring    1 ASCEW0B0 (0)   ASCE Word 0 Byte 0
    0000    0 Bitstring    1 ASCEBYT0       ASCE Byte 0
    0001    1 Bitstring    1 ASCEW0B1 (0)   ASCE Word 0 Byte 1
    0001    1 Bitstring    1 ASCEBYT1       ASCE Byte 1
    0002    2 Bitstring    1 ASCEW0B2 (0)   ASCE Word 0 Byte 2
    0002    2 Bitstring    1 ASCEBYT2       ASCE Byte 2
    0003    3 Bitstring    1 ASCEW0B3 (0)   ASCE Word 0 Byte 3
    0003    3 Bitstring    1 ASCEBYT3       ASCE Byte 3
    0004    4 Signed       4 ASCEW1 (0)     ASCE Word 1
    0004    4 Bitstring    1 ASCEW1B0 (0)   ASCE Word 1 Byte 0
    0004    4 Bitstring    1 ASCEBYT4       ASCE Byte 4
    0005    5 Bitstring    1 ASCEW1B1 (0)   ASCE Word 1 Byte 1
    0005    5 Bitstring    1 ASCEBYT5       ASCE Byte 5
    0006    6 Bitstring    1 ASCEW1B2 (0)   ASCE Word 1 Byte 2
    0006    6 Bitstring    1 ASCEBYT6       ASCE Byte 6
              .... ..1.      ASCEGBIT       X'02' Subspace-group control bit
              .... ...1      ASCEPBIT       X'01' Private-space control bit
    0007    7 Bitstring    1 ASCEW1B3 (0)   ASCE Word 1 Byte 3
    0007    7 Bitstring    1 ASCEBYT7       ASCE Byte 7
              1... ....      ASCESBIT       X'80' Storage-alteration-event
                                            control bit
              .1.. ....      ASCEXBIT       X'40' Space-switch-event control
                                            bit
              ..1. ....      ASCERBIT       X'20' Real-space control bit -
                                            R=0: ASCE is an RTD or STD - R=1:
                                            ASCE is an RSD
              .... 11..      ASCETBIT       X'0C' Designation type bits The
                                            following four designation type
                                            bits are valid only if the
                                            real-space control bit (ASCERBIT)
                                            = zero (R=0)
              .... 11..      ASCERFTD       X'0C' ASCE is an RFT designation
              .... 1...      ASCERSTD       X'08' ASCE is an RST designation
              .... .1..      ASCERTTD       X'04' ASCE is an RTT designation
              .... ....      ASCESTD        X'00' ASCE is an ST designation
              .... ..11      ASCELBIT       X'03' Table length bits

#### ASCE Storage Layout

    *** ASCE - Address-Space-Control Element
    *
    *
    *** ASCE - Address-Space-Control Element

    *** Overlay for ASCE in ASCE
    *
    *     +------+------+------+------+------+------+------+------+
    *   0 |:EBYT0|:EBYT1|:EBYT2|:EBYT3|:EBYT4|:EBYT5|:EBYT6|:EBYT7|
    *     +------+------+------+------+------+------+------+------+
    *   8
    *
    *** Overlay for ASCE in ASCE

#### ASCE Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    ASCEALL        0000
    ASCEBYT0       0000
    ASCEBYT1       0001
    ASCEBYT2       0002
    ASCEBYT3       0003
    ASCEBYT4       0004
    ASCEBYT5       0005
    ASCEBYT6       0006
    ASCEBYT7       0007
    ASCEDTMK       0000 0C
    ASCEDTSHF      0000 00000002
    ASCEGBIT       0006 02
    ASCEGSM        0000 00000200
    ASCELBIT       0007 03
    ASCEMSK        0000 00000AF0
    ASCEMSKL       0000 00000AF4
    ASCEPBIT       0006 01
    ASCEPSM        0000 00000100
    ASCERBIT       0007 20
    ASCERBM        0000 20
    ASCERFTD       0007 0C
    ASCERSTD       0007 08
    ASCERTTD       0007 04
    ASCESBIT       0007 80
    ASCESSM        0000 80
    ASCESTD        0007 00
    ASCETBIT       0007 0C
    ASCETLBYT      0000 0000000C
    ASCETLMK       0000 03
    ASCETOMH       0000 00FFFFFF
    ASCETOML       0000 00FFF000
    ASCEW0         0000
    ASCEW0B0       0000
    ASCEW0B1       0001
    ASCEW0B2       0002
    ASCEW0B3       0003
    ASCEW1         0004
    ASCEW1B0       0004
    ASCEW1B1       0005
    ASCEW1B2       0006
    ASCEW1B3       0007
    ASCEXBIT       0007 40
    ASCEXSM        0000 40

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 17:41:10 EDT.
Copyright IBM Corporation, 1990, 2005