Can I use a Kodak SD memory card with my Canon Powershot A540 digital camera?

It doesn't matter what brand memory card you use for a particular camera

I have a Canon digital SLR and have used cards from multiple manufacturers.

Regarding formatting - the camera will do that for you. Just delete all current files and you are good to go

Yes, but you'll probably have to reformat the card in the Canon first.

Be careful about reformatting picture cards. There are lots of known incompatibilties with how computers format cards versus how cameras format them.
I would extract all pictures first then simply plop it into the new camera and start it up. More than likely you will be ok as is since most cameras will actually create their own folder name (to hold their pictures) on the SD card if they don't find one already there.