I was a hard time to complete these two exercise problem. The HCS12 Microcontrol

Question

I was a hard time to complete these two exercise problem. The HCS12 Microcontrollers and Embedded Systems, 1st Edition and codewarrior, I was not able to use it to solve this problem. I need help to solve this problem and due today? Thank you

Assume SP = $4000, and A = $FE, after executing PSHA:

SP = $4001, A = $FE, and M[$4000] = $FE

SP = $3FFF, A = $FE, and M[$4000] = $FE

SP = $3FFD, A = $FE, and M[$3FFF] = $FE

SP = $3FFF, A = $FE, and M[$3FFF] = $FE

Assume SP = $3FFA, M[$3FFA] = $55, after executing PULA:

SP = $3FF9, M[$3FFA] = $55, and A = $55

SP = $3FFB, M[$3FFA] = $55, and A = $55

SP = $3FFB, M[$3FFB] = $55, and A = $FA

SP = $3FFC, M[$3FFB] = $FB, and A = $FB

Explanation / Answer

PSHA -> push accumulator onto the stack.
So after executing PSHA, the A value is stored into accumulator.
So M[$4000] = SFE
and stack pointer moves to one position that is SP = $4001

So finally,

---------------------------------------------------------------------------------------------------------------------------------------------------------

PULA means pulling accumulator from accumulator..

It pulls acculumator M[$3FFA] = $55,, which is $55 into A

And stack pointer increases by 1. So Sp = 3FFA + 1 ===> 3FFB

So ,

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