btfsc instruction

gregmcc said:

I seem to having endless problems with this simple instruction.

If I have the following code:

movlw b'00000000'
btfsc W, 0
goto Intrusion
goto Main

According to the datasheet - btfsc: If bit is set then skip next instruction. On the above bit zero is clear so it should execute the next instruction. Why's it that my mode keeps jumping to Main

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gregmcc said:

Thanks - that might explain why I was having trouble

I've done a search through the 16F62X datasheet and under the BTFSC instruction it doesn't mention anything about not using the W register. Unless of course I'm not reading it correctly, which by this stage anything is possible. <grin>

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To test bit 0 of W you can do the following,

Code:

Code:

 andlw  b'00000001'
     btfss  STATUS,Z
     goto   BitWasOne

To test a different or multiple bits just change the 0's to 1's.
The above does of course corrupt W.

Mike.

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gregmcc said:

Thanks - I'll paste that right into my code

Click to expand...

movlw b'00000000' 
movwf Temp
btfsc Temp, 0
goto Intrusion
goto Main

Pommie said:

To test bit 0 of W you can do the following,

Code:

     andlw  b'00000001'
     btfss  STATUS,Z
     goto   BitWasOne

To test a different or multiple bits just change the 0's to 1's.
The above does of course corrupt W.

Mike.

Click to expand...

Ayne said:

Above code is right???
plz guide me that
if W = 0000 0001 AND Litrel = 0000 0001 then Z = ???

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