Type ASSEMBLE
Source Lines : 898
Fixes Applied : 1
Most Recent Version : Wednesday, December 13, 1978
Last Fix ID : [HRC013DK]
Module
DMKTMR
Function
TO SIMULATE THE CPU TIMER AND TIME OF DAY CLOCK COMPARATOR
INSTRUCTIONS FOR VIRTUAL SYSTEM 370'S OPERATING IN EXTENDED
CONTROL MODE
Attributes
REENTRANT, RESIDENT, ENTERED VIA GOTO FROM DMKPRV
Operation
SECTION A. - INITIALIZATION
1. IF THE OPERATION IS SCK, SKIP TO STEP 3; OTHERWISE, CON-
TINUE
2. IF THE USER IS NOT IN EXTENDED PSW MODE, REFLECT AN OPER-
ATION EXCEPTION
3. GET THE ADDRESS SPECIFIED IN THE INSTRUCTION; IF IT IS NOT
DOUBLE WORD ALIGNED, REFLECT A SPECIFICATION EXCEPTION
4. TRANS FOR USER DATA PAGE; IF THE RESULTING CONDITION CODE
INDICATES A VIRTUAL ADDRESSING ERROR, REFLECT IT
5. IF THE INSTRUCTION IS NOT A STORE (2ND OPCODE BYTE IS NOT
ODD), SKIP TO STEP 7; OTHERWISE, CONTINUE
6. COMPARE THE VIRTUAL PSW KEY TO THE STORAGE KEY IN THE
USER'S PAGE; IF THEY DO NOT AGREE AND IF THE PSW KEY
IS NON-ZERO, REFLECT A PROTECTION EXCEPTION
7. GET THE 2ND OPCODE BYTE AND BRANCH TO HANDLE THE REQUESTED
INSTRUCTION AS DESCRIBED IN SECTIONS B THROUGH F BELOW
Calls to Other Routines
DMKPTRAN - TO LOCATE THE USER'S DATA AREA IN HIS VIRTUAL
MEMORY
DMKPSAFP - TO CHECK FOR FETCH PROTECTION
DMKPSASP - TO CHECK FOR STORAGE PROTECTION
INSTRUCTIONS
DMKSCHST - TO ESTABLISH A TOD COMPARATOR INTERRUPT REQUEST
DMKSCHRT - TO RESET A TOD COMPARATOR INTERRUPT REQUEST
DMKSTKIO - TO STACK A PENDING CLOCK COMPARATOR INTERRUPT
DMKDSPCH - EXIT VIA GOTO IF INTERRUPT IS PENDING
DMKPRGSM - EXIT VIA GOTO TO REFLECT A PROGRAM INTERRUPT
DMKSTKDE - TO STACK A DEFERRED USER TASK
DMKDSPRU - TO RUN USERS WITHOUT SYSTEM LOCK