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ibm:vm370-lib:cms:dmshdi.assemble_abs

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DMSHDI Abstract

Statistics

Type ASSEMBLE
Source Lines : 389
Fixes Applied : 1
Most Recent Version : Tuesday, December 12, 1978
Last Fix ID : [R09008DS]

Synopsis

Module

       DMSHDI

Function

       TO SET THE CMS INTERRUPT HANDLING FUNCTIONS TO TRANSFER CON-
       TROL TO A GIVEN LOCATION FOR AN I/O DEVICE OTHER THAN THOSE
       NORMALLY HANDLED BY CMS, OR TO CLEAR PREVIOUSLY
       INITIALIZED I/O INTERRUPT HANDLING.

Attributes

       REENTRANT, DISK RESIDENT, AND EXECUTES IN THE TRANSIENT AREA

Operation

       1.  PROGRAM INITIALIZES HANDLING TO BE DONE VIA 'HNDINT SET'

       2.  WHEN I/O TO APPROPRIATE DEVICE IS TO BE DONE,
           SYSTEM-MASK IS SET 'OFF'  (BY 'SSM' INSTRUCTION)
           AND APPRORPATE 'SIO' GIVEN.

       3.  WHEN 'SIO' PERFORMED SATISFACTORILY, SYSTEM-MASK CAN BE
           SET TO ALLOW ALL INTERRUPTS.

       4A. IF 'ASAP' WAS SPECIFIED, INTERRUPT-HANDLER IS INVOKED AS
           SOON AS THE INTERRUPT IS 'FIELDED' BY CMS 'IOINT'
           INTERRUPT-HANDLER RETURNS TO 'IOINT' WHICH RETURNS TO PROG

       4B. IF 'ASAP' WASN'T SPECIFIED, 'IOINT' RETAINS NEEDED
           INFORMATION UNTIL CMS 'WAIT' FUNCTION IS CALLED.

       5.  WHEN PROGRAM 'NEEDS' THE INTERRUPT TO HAVE BEEN RECEIVED,
           CMS 'WAIT' FUNCTION IS CALLED.  IF INTERRUPT HAS NOT
           YET BEEN RECEIVED, CMS GOES IN 'WAIT' STATE UNTIL 'IOINT'
           FIELDS AND PROCESSES THE INTERRUPT IN NORMAL WAY.

           IF INTERRUPT HAS BEEN RECEIVED & PROCESSED (E.G. ON 'ASAP'
           RETURNS TO CALLER WITH NECESSARY INTERNAL FLAGS CLEARED.

           IF INTERRUPT HAS BEEN RECEIVED BUT NOT YET PROCESSED
           (AS UNDER 'WAIT' OPTION INSTEAD OF 'ASAP'), CMS 'WAIT'
           NOW CALLS IOINT TO INVOKE DESIRED INTERRUPT-HANDLER,
           THEN CLEARS NEEDED FLAGS AND RETURNS TO CALLER.

       6.  WHEN THRU, USING PROGRAM SHOULD NORMALLY CLEAR
           THE INTERRUPT-HANDLING SCHEME THRU 'HNDINT CLR' CALL
           (UNLESS 'KEEP' OPTION IS USED & INTERRUPT-HANDLER
           REMAINS INTACT IN CORE)

Calls to Other Routines

       TYPLIN - TYPE A MESSAGE ON THE TERMINAL
       FREE - GET FREE STORAGE
       FRET - RETURN FREE STORAGE
ibm/vm370-lib/cms/dmshdi.assemble_abs.txt ยท Last modified: 2023/08/06 13:35 by Site Administrator