HC12 question

  • Thread starter seang
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  • #1
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Main Question or Discussion Point

I cannot understand why the following bits are equivalent:

Code:
LDAA 0,X
INCX
;and
LDAA 1,X+

The 1 is throwing me off. Since the X register is post incremented, why is it necessary? I would think that LDAA 0,X+ would be equivalent to the first bit of code. What am I missing?
 

Answers and Replies

  • #2
berkeman
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I don't program in HC 12 assembly, but is the first arguent to the LDAA instruction the register number?
 
  • #3
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Right, I was thinking that might be a problem.

LDAA 0,X loads the A accumulator with the address stored in the X register, plus the offset (0, in this case).

LDAA 1,X+ loads the A accumulator with the address in the X register, plus the offset (1 in this case), and then increments the X register.
 
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