Why is LDAA 0,X Equivalent to LDAA 1,X+?

[seang]

I cannot understand why the following bits are equivalent:

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?

 

[berkeman]

I don't program in HC 12 assembly, but is the first arguent to the LDAA instruction the register number?

 

[seang]

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.