Altera FPGA (?) Datasheet
The EPC devices are usually configuration devices (flash memory) not FPGAs. The Cyclone III FPGA part numbers would instead begin with EP3C (Cyclone III), and not EPC3.

You are correct there doesn't seem to be a matching part number. However I believe you may have misread the 3, and it is actually a 2.

That gives EPC2TC32, which is indeed an, albeit obsolete, Altera flash memory device. This is a 1.6Mbit Configuration Flash memory in a TQFP-32 package.