HP 68302 User Manual page 110

Chapter 4: Plugging the Emulator into Target Systems
Configuring the Emulator for In-Circuit Operation
Modify your emulator configuration to specify a foreground monitor,
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specify the address you chose and the filename you created (in this
example, the filename is FGMON.X for the Microtec or HP AxLS
linker).
Make sure that the address range 0FFF000H through 0FFFFFFH is
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mapped as "target RAM". This is important because the emulator will
attempt to access the on-chip locations of the 68302 upon entering
the monitor. It uses the default address for the BAR, placing the
internal register section at address 0FFF000H. Leaving this as
guarded will cause a guarded access error, mapping it to emulation
RAM will cause unpredictable results.
If You Plan to Single-Step
If you plan to single-step when using the foreground monitor there's one
more thing you need to do. You need to ensure that the vector table entry at
location 24H points to the label "TRACE_ENTRY" in the foreground monitor
module. You can determine what this address is by looking at the listing file
created when you assembled the monitor. There are many approaches you
can take to ensure this, including:
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•
•
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Modify your own code to place the value of TRACE_ENTRY at location
24H. This is probably the most robust method because you can account
for things such as a RAM-based vector table that is loaded by your
initialization code.
Use a modify memory command to put the value of TRACE_ENTRY at
24H after loading your program. This works fine if your program doesn't
overwrite or re-initialize the vector table during execution.
Use a command file to single step that first modifies memory location
24H to point to TRACE_ENTRY, then steps. For example:
MEMORY FILL LONG 24..27 XXXXXXH
STEP
where XXXXXXH is the address of TRACE_ENTRY
You shouldn't need to use this method unless your program or operating
system is continuously changing the vector table contents.