Using Software Breakpoints - HP H8/3003 User Manual

Using Software
Breakpoints
Note
Note
Displaying and
Modifying the Break
Conditions
bc -d bp #disable
bc -e rom #enable
bc -d bnct #disable
bc -d cmbt #disable
You can stop program execution at specific address by using bp
(software breakpoint) command. When you define a software
breakpoint to a certain address, the emulator will replace the opcode
with one of undefined opcode (5770 hex) as software breakpoint
instruction. When the emulator detects the special instruction, user
program breaks to the monitor, and the original opcode will be placed
at the breakpoint address. A subsequent run or step command will
execute from this address.
If the special instruction was not inserted as the result of bp command
(in other words, it is part of the user program), the "Undefined software
breakpoint" message is displayed.
You can set software breakpoints only at memory locations which
contain instruction opcodes (not operands or data). If a software
breakpoint is set at a memory location which is not an instruction
opcode, the software breakpoint instruction will never be executed and
the break will never occur.
Because software breakpoints are implemented by replacing opcodes
with the software breakpoint instruction, you cannot define software
breakpoints in target ROM. You can, however, copy target ROM into
emulation memory by cim command. (Refer to HP 64700 Terminal
Interface User's Reference manual.)
Before you can define software breakpoints, you must enable software
breakpoints with the bc (break conditions) command. To view the
default break conditions and change the software breakpoint condition,
enter the following commands.
M> bc
Getting Started 2-27