PAG39

PAG39 Prolog

 Name       : HCPPAG39
 Description: ESA/390 Page Table Entry
 DSECT      : PAG39
 Function   : A Page Table Entry is a hardware architected
              area that describes one 4K page of virtual
              storage.

PAG39 Control Block Content

PAG39 DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      PAG39          ESA/390 Page Table Entry
0000    0 Signed       4 PAGENTRY       ESA/390 Page Table Entry
          00000004       PAGLENTH       *-PAGENTRY Length of 1 ESA/390
                                        PTE
0004    4 Signed       4 PAGNEXT (0)    Next ESA/390 Page Table Entry
0000    0 Bitstring    1 *              Bits 1-7 of the page frame real
                                        address. Bit 0 must be 0 in a
                                        valid ESA/390 PTE.
0001    1 Bitstring    1 *              Bits 8-15 of the page frame real
                                        address.
0002    2 Bitstring    1 PAGSTAT        Bits 0, 20, and 23 must be zero.
          .... .1..      PAGINVAL       X'04' Page Table Entry is invalid
          .... ..1.      PAGPROT        X'02' PTE is page protected (read
                                        only)
0003    3 Bitstring    1 *              Reserved

PAG39 Storage Layout

          
*** PAG39 - ESA/390 Page Table Entry
*
*     +---------------------------+
*   0 |         PAGENTRY          |
*     +---------------------------+
*
*** PAG39 - ESA/390 Page Table Entry
          
*** Overlay for PAGENTRY in PAG39
*
*     +------+------+------+------+
*   0 |//////|//////|:STAT |//////| 4
*     +------+------+------+------+
*
*** Overlay for PAGENTRY in PAG39

PAG39 Cross Reference

Symbol         Dspl Value
-------------- ---- -----
PAGENTRY       0000
PAGINVAL       0002 04
PAGLENTH       0000 00000004
PAGNEXT        0004
PAGPROT        0002 02
PAGSTAT        0002