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can someone check if this is correct please

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steve98

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68000 assembler

1. The problem statement

If the content of d0 is $30 state in words what each of the following numbered instruction pairs will do.


2. Relevant QUESTION

a) cmpi #$30,d0
beq dan

b) cmp.l unknown,d0
bne dan

c) cmp.w d1,d0
bgt dan

3. The ANSWER

a)cmpi #$30,d0 = Since d0 is $30, the compare instruction sets the Z flag.
beq dan = [go to label dan] [if d0] [equal to zero]


b) cmp.l unknown,d0 = I don’t know what value stored in unknown. Therefore their will be three cases (unknown > d0 or unknown < d0 and unknown = d0)

Unknown > d0 = N flag gets set.
Unknown < d0 = no flags get set
unknown = d0 = Z flag gets set

bne dan = [go to label dan] [if d0] [not equal to zero]


c)cmp.w d1,d0 = I don’t know what value stored in d1. Therefore their will be three cases (d1 < d0 or d1 > d0 and d1 = d0)

d1 > d0 = N flag gets set.
d1 < d0 = no flags get set
d1 = d0 = Z flag gets set

bgt dan = [go to label dan] [if d0] [greater than zero]
 

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