Found a piece of code I don't understand

[AGCB]

In Nigel's tutorial 8 (PWM) there is a bit of code i don;t understand, in the 2nd paragraph of the initialize routine.

MOVF CCP1CON,w ;set CCP1 as PWM
ANDLW oxof
IORLW ox0c
MOVWF CCP1CON

Would someone explane this to me line by line with resulting values. I guess I would have done a MOVLW, MOVWF type of instruction

I'm expecting to learn a new trick!!!

Aaron

 

[Pommie]

He is leaving the bottom two bits unchanged. AND 0x0f zeroes the top 4 bits and IOR 0x0c sets bits 2 and 3.

Mike.

 

[Nigel Goodwin]

Like Mike explained, it's to change specific bits only.

I did it that way simply to isolate the different bit settings to show them better, rather than doing it all in one instruction.

 

[AGCB]

Thanks. I'll remember this. For me, not having hex in my head, using bin is easier with the movlw,movwf instructions.
Aaron