Logical difference between 2 8-bit ports XOR?

I'm trying to use XOR, and don't get it. I want an 8-bit binary number showing the difference between two 8-bit ports.... i.e. port X reads one thing, port Y reads another thing, how are they different. How do you do it, because this does not work...

Code:

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    I2CREAD SDA1,SCL1,DJAM,[X]
    X=X^%11111111

    I2CREAD SDA1,SCL1,IRS,[Y]
    Y=Y^%11111111
   
    Z= (X XOR Y)
   
    DEBUG BIN8 Z,10,13

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The ports are different, but this returns all 1's.

Thanks!

Quote:

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Originally Posted by circuitpro

Z= (X XOR Y)
The ports are different, but this returns all 1's.

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XOR is a "Logical operator", same as (^^).

To find the "bitwise" difference, you'll need the "bitwise" operator (^).
Just like in your previous statements ...

X=X^%11111111

Y=Y^%11111111

talk about having the answer and not knowing it. Thanks. :confused: