Microchip Technology MPLAB ICE, User Manual

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2001 Microchip Technology Inc. DS51159B-page 167
Migrating from PICMASTER
C.6 Setting Break Points
The following table shows the break point type and capacity of the three
emulators:
Software break points differ from hardware break points in that software break
points do not “skid.” If a break point is set at program memory address 100,
then the processor is halted before the instruction at address 100 is executed.
The program counter value will be 100 when emulation halts. With hardware
break points, at a minimum the instruction at location 100 will be executed.
Depending on the conditions set with the hardware break point, one or more
additional instructions may be executed.
Hardware break points are set on the MPLAB ICE emulator through the
Complex Trigger dialog (Debug>Complex Trigger Settings). Simple hardware
break points can also be set through the right mouse button.
C.6.1 Complex Triggers vs. Break/Trace/Trigger Points
PICMASTER allowed you to specify each program memory address as zero
or more of the following:
• a break point, whose execution halts emulation.
• a trace point, whose execution appears in the trace window.
• a trigger point, whose execution causes an external signal to be gener-
ated.
MPLAB ICE maintains this functionality, but through a different mechanism.
Software break points are set through the Break Point Settings dialog
(Debug>Break Settings) or the right mouse button. Hardware break points are
set through the Complex Trigger dialog (Debug>Complex Trigger Settings) by
specifying Halt On Trigger, or the right mouse button. Either one of these will
halt emulation.
Trace is handled slightly differently in MPLAB ICE. By default, all program
execution is traced. Simply open the trace memory window (Windows>Trace
Memory) to view the trace of the last execution. If only certain events are
desired to be in the trace, a Filter Trace complex trigger can be used to filter
the trace.
Trigger points can be obtained in MPLAB ICE by using a Filter Trace complex
trigger to generate a trigger on the desired operation. Then the Trigger In/Out
Settings dialog (Debug>Trigger In/Out Settings) can be used to generate an
external signal pulse whenever one of the complex trigger events occurs.
Break Point Comparison
Type PICMASTER MPLAB ICE
Software None Unlimited
Hardware Unlimited Unlimited