Program Execution Commands; Trace [Ninstr] - Fujitsu F2MC-16L Series User Manual

3.4. Program Execution Commands

3.4.1. TRACE [
Trace Instruction
The TRACE command can be used to single step an User program, beginning at the PCB:PC
register address. 'nInstr' specifies the number of instructions which shall be executed
automatically. If not specified, the trace will start in interactive mode.
>trace 11↵
... 17 (decimal) instructions are executed after this.
NOTE: The Program Address Counter can be set to a specific address using the "R IP val"
command prior to using the trace command.
>register IP fb3305↵
The interactive operation works according to the following loop.
LOOP
•
The monitor displays the actual register values and prints the disassembled instruction. If
source addresses data or destination addresses are used (e.g. direct 16 bit address or EA-
address), these are displayed with address and the value before execution. (See IOREAD
command.)
•
Then the User is prompted to press the 'SPACE', 'RETURN', 'O', 'R', 'V', 'B' or 'N' key to
execute the instruction or press any other key to abort the trace operation.
•
Continue loop if not aborted.
This way, the register values are always displayed before and after executing an instruction.
Special key functions:
• •
'SPACE' or 'RETURN' will execute one instructions at a time.
•
If 'O' is used at a CALL subroutine instruction, the subroutine is executed without tracing
(trace over).
•
If 'R' is used at a Branch instruction, a taken branch will not be traced.
This means, the Trace point is set only at the instruction following the current one. As long
as the program reaches this branch instruction and the condition causes to branch to the
alternative following address, control will not be gained back by the Monitor. Only if the
condition is not met the program will reach the Trace point and return to the Monitor
• •
'V' is the counterpart of 'R'. Only the branch is traced. The Trace point is set only at the
alternative following address. The program is executed as long as the branch condition is
not met.
•
'B' causes to branch regardless of whether the condition is met or not.
• •
'N' is the counterpart of 'B'. The execution is continued at the next instruction after the
conditional branch regardless of whether the condition is met or not.
NOTE: If conditional branches are traced with special function 'B' or 'N' the normal
processing is changed. This might be used to influence processing. However, this can
also cause miss-operation of the User's program.
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FUJITSU MB90675-Evaluation Board - User Manual
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