HP 64783A, User Manual

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Software breakpoint entry into the background
monitor
The background monitor can also be entered via a software breakpoint. The
emulator will respond to any software breakpoint instruction in the code if
breakpoints are enabled, regardless of whether the breakpoint was inserted by the
emulator or not. Breakpoints are enabled by the following command.
bc -e bp
Set breakpoints only on the initial word of an instruction; otherwise, they will not
be executed, and might alter an instruction, unintentionally. The emulator can
place a breakpoint using one of two methods. By default, the emulator will attempt
to modify memory to insert a breakpoint instruction at the address specified. If the
memory at the address specified is ROM or cannot be modified for some other
reason, special hardware resources on the emulator will interject a breakpoint
instruction when that address is fetched.
b
bp <instruction address>
If you suspect a problem occurred during the setting of the breakpoint, you can use
the analyzer to watch the breakpoint being set. The easiest way to do this is to
store-qualify your trace on the address where you are setting the breakpoint. The
trace list will only contain a cycle or two, but you can see what happened when the
emulator accessed this address.
tg any
tsto addr=<instruction address>
b
bp <instruction address>
Line addr,H 68040 Mnemonic
----- -------- ------------------------------------------
0 00000008 $FFFF---- sdata word read
1 00000008 $FFFF---- sdata word read
2 00000008 $FFFF---- sdata word read
3 00000008 $484F---- sdata word write <- breakpoint write
4 00000008 $FFFF---- sdata word read <- verify
5 00000008 $FFFF---- sdata word read
6
Chapter 18: Connecting the Emulator to a Target System
Installing Emulator Features
646