Masking Upper Nibble

Suraj143 said:

Hi I need to mask the upper nibble & must not do any harm to the lower nibble.

But this code works but corrupting lower nibble.

Code:

	movf	Data,W
	andlw	b'11110000'
	movwf	PORTB,F

Click to expand...

	andlw	b'00001111'

kchriste said:

Do you wish to transfer the upper nibble of Data to the upper nibble of PORTB without disturbing the lower nibble in either?

Click to expand...

Suraj143 said:

Exactly this is what I need to do.

Click to expand...

futz said:

Then first move Data to a temp variable or W and mask the lower nibble. Then mask the upper nibble of PORTB (maybe move it to a temporary variable first). Then OR them together.

Maybe there's a simpler way?

Click to expand...

	movf	Data,W
	andlw	b'00001111'
	????	????
	iorwf	PORTB,F

futz said:

Code:

	movf	Data,W
	andlw	b'11110000'
	movwf	temp1
	movf	PORTB,w
	andlw	b'00001111'
	iorwf	temp1,w
	movwf	PORTB

Hmm... Is that right? Just quickly banged it out. Can't test it quickly.

Click to expand...