TOPS-10 Monitor Calls Manual Volume 2 AA-K039D ... - Trailing-Edge

APRENB [CALLI 16]
22 • 3 APRENB [CALLI 16]
FUNCTION
Enables trap servicing for a program. When a condition enabled for
trap servicing occurs, control is transferred to the address given by
.JBAPR in the job data area. See Chapter 6 for more information about
handling traps.
CALLING SEQUENCE
MOVE I
APRENB.
return
ac,flags
ac,
In the calling sequence, you can supply the following flags, indicated
by these flag bits:
Bit
. Symbol
Trap Condition
18 AP .REN
19 AP .,POV
21 AP.ABK
22 AP. ILM
23 AP.NXM
24 AP.PAR
26 AP .CLK
29 AP .FOV
32 AP.AOV
Repetitive enable.
Pushdown list overflow.
Reserved.
Memory protection violation.
Nonexistent memory.
Memory parity error.
Clock tick. The clock ticked while your program
was actively running; this trap does not occur for
every clock tick.
Floating-point overflow.
Arithmetic overflow.
When one of these conditions occurs whil~
mode, the monitor:
the processor is in user
1. Stores the PC in location .JBTPC in the Job Data Area. If
the PC is equal to the first or second location in your trap
servicing routine, the program is terminated.
2. Clears the arithmetic and floating-point overflow flags.
3. Transfers control to your trap-servicing routine; the
location is given by the right half of location .JBAPR in the
Job Data Area.
Your program must place the address of the trap-servicing routine into
.JBAPR before executing the APRENB monitor call.
22-5