Radstone PME 68-1B, Manual

Page: 86 / 132

Return to the Monitor
Return to the PME68/Monitor may be initiated via software. A useful means of doing
this from a user application program is:
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-- User Program --
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TRAP # 14
i.e. Adding a TRAP # 14 instruction at the end of the user program.
The other user Trap locations, from UT0 to UT13 and UT15, are preset with the
appropriate error handling routine, they can be used by application programs.
A coldstart of the Monitor (complete reinitialisation) is done via an indirect jump to the
initial start address ($4). Coldstart calls (i.e. pressing the RESET switch) should be
handled with care as the old status of the system is destroyed and breakpoints may be
lost from application programs.
The HALT Indicator
A red LED on the front panel indicates the status of the CPU, it is hardwired to the
HALT signal line of the processor. During normal operation the LED should not light.
If a failure occurs only a RESET can restart the CPU.
Note: The LED is not accessible by software.
PME68-1B Manual
Page 80 Issue 5