I believe you should read this thread,,,,it has some applicable information...in particular the stuff about the Infineon processors.

http://www.8052.com/forum/rea...%3A57%3A11

Then look also at these postings.....all about sinusoidal generation with some PWM references.

http://www.semiconductors.philips.com/files/pro...s/dtmf.zip

http://www.silabs.com/products/pdf/an123rev1_1.pdf

http://www.maxim-ic.com/appnotes....1858/ln/en

http://www.audiomulch.com/~rossb/code/sinusoids/

http://www.microchip.com/download/...00543c.pdf

http://www.electrosnab.ru/component...1_sine.pdf

http://www.atmel.com/dyn/resou...OC1982.PDF

Michael Karas