Note
Because software breakpoints are implemented by replacing opcodes
with BRK instructions, you cannot define software breakpoints in
target ROM.
Note
Software breakpoints should not be set, cleared, enabled, or disabled
while the emulator is running user code. If any of these commands are
entered while the emulator is running user code, and the emulator is
executing code in the area where the breakpoint is being modified,
program execution may be unreliable.
When software breakpoints are enabled and emulator detects a fetching
the BRK instruction, it generates a break to background request which
as with the "processor break" command. Since the system controller
knows the locations of defined software breakpoints, it can determine
whether the BRK instruction is software breakpoints or opcode in your
target program.
If it is a software breakpoint, execution breaks to the monitor,and the
BRK instruction is replaced by the original opcode. A subsequent run
or step command will execute from this address.
If the BRK instruction is opcode of your target program, execution still
breaks to the monitor, and an "Undefined software breakpoint" status
message is displayed.
When software breakpoints are disabled, the emulator replaces the
special code with the original opcode.
Up to 32 software breakpoints may be defined.
Getting Started 2-21
Summary of Contents for 64146A
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Page 8: ...Notes ...
Page 14: ...Notes 6 Contents ...
Page 16: ...Figure 1 1 HP 64146 Emulator for MELPS 7700 Series 1 2 Introduction ...
Page 60: ...Notes 3 4 In Circuit Emulation ...
Page 92: ...Notes 5 10 Using the Emulator ...