Introduction To CodeWarrior™ – Simulating The - Freescale ...

2. Click the Green Start/Continue Arrow or click Run > Start/Continue. The program should run to your breakpoint and stop.
(Note: A breakpoint stops the program before it executes that statement.)
3. Now, step through your program one assembly language statement at a time by clicking on the single-step button or pressing
F11 until you reach the nop instruction
at the beginning of the program again.
(We will see what the LDS instruction is
all about later.)
4. At each step inspect the Register window to see what is happening to the registers. Try to predict what will happen at each
step BEFORE
you click on the step button.
Stimulate 3.
1. Under what circumstances does it make sense to run and debug your programs in the simulator?
2. When would you want to run and debug your programs using the hardware debugger?
Skill Exercise 1
1. Double click on each of the register boxes in the Register window and enter a value of zero for each register. You won't be
able to change the CCR.
2. Press the Reset Target button (or type control-R) to return the program to the initial reset state.
3. Single-step through the program and complete a table showing
the result of each instruction. The CCR (Condition Code
Register) bits NZVC a re shown bold w hen th e bit is set.
Instruction D A B IX IY PC SP NZVC
Reset state 00 00 00 00 00 00 00 00 C000 FFFE 00 00
lds
#__SEG_END_SSTACK
nop
ldx #ConstData
ldab #$02
ldaa 0,x
staa VarData
ldaa 2,x
staa VarData+1
inx
decb
bne loop
ldaa 0,x
staa VarData
ldaa 2,x
staa VarData+1
inx
decb
bne loop
Freescale Semiconductor LABS12CINTRO03S, Rev 1 7