however, I recommend you choose a derivative with a PCA, 3 phases without a PCA can be quite complex. When a 3 phase motor is involved $1 more for the uC should not be a showstopper.

as an 'example device' have a look at the NXP P89V51RD2 or the SILabs 8051f120

Erik

PS, if you go with a PCA device, have a look at The PCA cookbook
http://www.intel.com/design/mc...270609.htm