SEG37 Back to Index page
 
Prolog 
Control Block Contents 
   SEG37 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.


  SEG37 Prolog Top of page
 
 NAME       : HCPSEG37
 DESCRIPTION: Segment Table Entry for 370
 DSECT      : SEG37
 FUNCTION   : The following maps the segment table entry in the
              System/370 architecture.
              The format of the 370 segment table entry is
              architected and cannot be changed in any way
              which violates the architecture.
 RELOCATION CONSIDERATIONS : None
 
 
  SEG37 Control Block Content Top of page
 

 SEG37 DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure SEG37 Segment Table Entry for 370 0000 0 Signed 4 SEG3ENTR (0) System/370 Segment Table Entry 0000 0 Bitstring 1 * Page table length in left nibble and right nibble must be 0. 0001 1 Bitstring 1 * Part of page table address 0002 2 Bitstring 1 * Part of page table address 0003 3 Bitstring 1 SEG370ST Segment table entry status for 370 non-extended architecture. Leftmost 5 bits comprise part of the page table address. Rightmost 3 bits are the status. .... .1.. SEG370PR X'04' SEG370PR Segment is write protected .... ..1. SEG370CO X'02' SEG370CO Segment is a common segment .... ...1 SEG370IV X'01' SEG370IV Segment is invalid 00000004 SEG3LENT *-SEG3ENTR Length of one 370 STE 0004 4 Signed 4 SEG3NEXT (0) Next 370 STE SEG3NEXT SEG3PTOM X'00FFFFF8' SEG3PTOM Isolate page-table origin in S/370 architecture STE .... ...1 SEG3INVM X'00000001' SEG3INVM Isolate segment-invalid bit in S/370 architecture STE .... ..1. SEG3COMM X'00000002' SEG3COMM Isolate common-segment bit in S/370 architecture STE .... .1.. SEG3PROM X'00000004' SEG3PROM Isolate segment-protection bit in S/370 architecture STE .... .... SEG3PTLM X'F0000000' SEG3PTLM Isolate page-table length in S/370 architecture STE .... ...1 SEG3RSVM X'0F000001' SEG3RSVM Reserved bits, must be 0 in any valid S/370 architecture STE END OF DEFINITION
 
 
  SEG37 Storage Layout Top of page
 
 
*** SEG37 - Segment Table Entry for 370
*
*     +------+------+------+------+
*   0 |//////|//////|//////|:370ST|
*     +------+------+------+------+
*
*** SEG37 - Segment Table Entry for 370
 
 
  SEG37 Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
SEG3COMM       0004 02
SEG3ENTR       0000
SEG3INVM       0004 01
SEG3LENT       0003 00000004
SEG3NEXT       0004
SEG3PROM       0004 04
SEG3PTLM       0004 00
SEG3PTOM       0004 SEG3NEXT
SEG3RSVM       0004 01
SEG370CO       0003 02
SEG370IV       0003 01
SEG370PR       0003 04
SEG370ST       0003
 
This information is based on z/VM 6.4.0 Last updated on 24 Aug 2016 at 09:43:19 EDT.
Copyright IBM Corporation, 1990, 2016