Trace To Temporary Breakpoint - Motorola M68CPU32BUG User Manual

TT

3.33 TRACE TO TEMPORARY BREAKPOINT

TT <addr>
Use the TT command to set a temporary breakpoint at a specified address and trace until
encountering a 0 count breakpoint. The temporary breakpoint is then removed (TT is analogous
to the GT command) and control is returned to CPU32Bug. Tracing starts at the target PC
address. As each instruction is traced, a register display printout is generated.
During tracing, breakpoints in ROM or write protected memory are monitored (but not inserted)
for all trace commands which allow the use of breakpoints. Control is returned to CPU32Bug if a
breakpoint with 0 count is encountered. See the trace (T) command for more details.
The trace functions are implemented with the trace bits (T0, T1) in the MCU status register. Do
not modify trace bits (T0, T1) while using the trace commands. Because the trace functions are
implemented using the hardware trace bits in the MCU, code in ROM can be traced. During trace
mode, breakpoints are monitored and their counts decremented when the corresponding
instruction with breakpoint is traced. This allows breakpoints to work in ROM, but only in the
trace mode.
EXAMPLE The following program resides at location $7000.
CPU32Bug>MD 7000;DI<CR>
00007000 2200
00007002 4282
00007004 D401
00007006 E289
00007008 66FA
0000700A E20A
0000700C 55C2
0000700E 60FE
CPU32Bug>
Initialize PC and D0:
CPU32Bug>RM PC<CR>
PC =00008000 ? 7000.<CR>
CPU32Bug>RM D0<CR>
D0 =00000000 ? 8F41C.<CR>
M68CPU32BUG/D REV 1
Trace To Temporary Breakpoint
MOVE.L
CLR.L
ADD.B
LSR.L
BNE.B
LSR.B
SCS.B
BRA.B
3-66
DEBUG MONITOR COMMANDS
D0,D1
D2
D1,D2
#$1,D1
$7004
#$1,D2
D2
$700E
TT