Bitwise operations and masks: basics, help?

[xnihilo]

when you want to clear a bit you use AND, set a bit OR

portc: x11111

PORTC=PORTC | %00011111

<hr>
porta: xxxx10x,

for this one you may also do it simple..
TempVar=PORTA
TempVar.1=0
TempVar.2=1
PORTA=TempVar

OR, in some case, the following will work without much problem
PORTA.1=0
PORTA.2=1

HTH

Hello,

Simple?
Not so simple because each digit on the 7segments display needs (in my design) a pair of bytes for porta and portc that are found in a 10 entries array, and I prefer not to use intermediate variable.
Sorry but I didn't understand your example above:

portc: x11111
PORTC=PORTC | %00011111
porta: xxxx10x,



let's say porta value is %00011001 and I need to alter only bits 1 and 2 with the following pattern stored in a BYTE varible called "avar":
variable avar value is %-----10-

???

Can I isolate a chunk of a byte and insert it at a desired position in anoter byte?