Ron Stone <PICLIST@MITVMA.MIT.EDU> wrote:

> I've been reviewing section 29 (instruction set) of this manual
> (DS31029A)) and have found a couple of examples that I don't understand.
> Perhaps they're errors, but probably not. On pg. 29-29 (MOVF) Example 1:
>
> MOVF  INDF, 0
>
> Before Instruction
>     W=  0x17
>     FSR=0xC2
> Contents of Address (FSR) = 0x00
> After Instruction
>     W = 0x17
>    FSR= 0xC2
> Contents of Address (FSR)= 0x00
>   Z=1
>
> Is this correct?

    No; the result in the manual would be correct after a
    "MOVWF INDF" instruction.  After the "MOVF INDF,0"
    instruction, the results should be:

        W = 0x00
        FSR = 0xC2 (unchanged)
        Contents of Address (FSR) = 0x00 (unchanged)
        Z = 1

> What would happen if the instruction had been: MOVF  INDF, 1 ?

        W = 0x17 (unchanged)
        FSR = 0xC2 (unchanged)
        Contents of Address (FSR) = 0x00 (unchanged)
        Z = 1

> On pg. 29-36 (RLF) and similarly for 29-37 (RRF) we have Example 2
>
> RLF  INDF,1
> Before Instruction
>   W= xxxx xxxx
>   FSR= 0xC2
>   Contents of Address (FSR) = 0011 1010
>   C=1
> After Instruction
>   W= 0x17
>   FSR= 0xC2
>   Contents of Address (FSR) = 0111 0101
>   C=0

    This is also wrong; after the RLF, the results are:

        W = uuuu uuuu (unchanged)
        FSR = 0xC2 (unchanged)
        Contents of Address (FSR) = 0111 0101
        C = 0

    -Andy


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