Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

LCDA

Prolog  

Control Block Contents  

LCDA DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

LCDA Prolog

 Name       : HCPLCDA
 Description: Locate data area
 STATUS     : VM/ESA Version 2, Release 3.0
 DSECT      : LCDA
 Function   : Maps the contents of the Locate data
              area.
 Located by :
              HCCWADDR - The Locate CCW data address field
              contains the address of the locate
              data area.
 Created by :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Paging I/O manager -
              The data area resides in the HCPPIOBK which
              is allocated by HCPRDA.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build FBA channel programs
              which is allocated in modules HCPFTU/HCPFTP.
 Deleted by :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Paging I/O manager -
              The data area resides in the HCPPIOBK which
              is allocated by HCPRDD.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build FBA channel programs
              which is deallocated in modules HCPFTU/HCPFTP.
 Serialized :
              Paging I/O manager -
              EXPLCKFG - The paging I/O manager uses the exposure
              block lock to serialize this data area.
              Track cache manager -
              TCMTSLK  - Track cache lock
 Comments   :
              Paging I/O manager -
              The Locate data area resides in the HCPPIOBK.
              Each Locate CCW address field contains the
              address of the Locate data
              area within that PIOBK.
              Track cache manager -
              None

 

LCDA Control Block Content


LCDA DSECT

Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure LCDA Locate data area 0000 0 Bitstring 8 LCDAREA (0) Locate data area Byte 0 (Operation byte) Although defined as BITs, the contents of the operation byte are, architecturally, multiple codes. 0000 0 Bitstring 1 LCDOP Operation byte .... .... LCDZEROS X'00' Operation byte, bits 0 - 3 .... 1111 LCDOOC X'0F' Operation byte, bits 4 through 7 ------- Codes for use with LCDOOC .... ...1 LCDOCWD X'01' Write data .... ..1. LCDOCRR X'02' Read Replicated Data .... .1.. LCDOCFD X'04' Format defective block .... .1.1 LCDOCWC X'05' Write and Check Data .... .11. LCDOCRD X'06' Read data ------- Byte 1 (Locate Replication Count) 0001 1 Bitstring 1 LCDRPCNT Replication count Bytes 2 and 3 (Block Count): Block count is the number of addressable blocks to be processed. 0002 2 Bitstring 2 LCDBKCNT Block count Bytes 4 through 7 (Block address): Block address is the addressable block number of the first block to be processed in the data space. 0004 4 Bitstring 4 LCDBLOK Block address Length equates 00000008 LCDBSIZE *-LCDAREA Size of LCDA in bytes 00000001 LCDSIZE ((*-LCDAREA)+7)/8 Size of LCDA in DWs

 

LCDA Storage Layout

*** LCDA - Locate data area
*
*     +------+------+-------------+---------------------------+
*   0 |LCDOP |:RPCNT|  LCDBKCNT   |         LCDBLOK           |
*     +------+------+-------------+---------------------------+
*   8
*
*** LCDA - Locate data area

 

LCDA Cross Reference

(contains links to field and bit definitions)
Symbol         Dspl Value
-------------- ---- -----

LCDAREA 0000

LCDBKCNT 0002

LCDBLOK 0004

LCDBSIZE 0004 00000008

LCDOCFD 0000 04

LCDOCRD 0000 06

LCDOCRR 0000 02

LCDOCWC 0000 05

LCDOCWD 0000 01

LCDOOC 0000 0F

LCDOP 0000

LCDRPCNT 0001

LCDSIZE 0004 00000001

LCDZEROS 0000 00


This information is based on VM/ESA 2.4.0.
Last updated on 3 Aug 1999 at 12:08:08 EDT.
Copyright IBM Corporation, 1990, 1999