On the 128 pin part there are 4 lines of markings. The first is the label EZ-USB FX. The second is the part number CY7C64613-128NC. The third line is a 4 digit date code. YYWW format, where YY is two digit year. WW is week number that the part came out of manufacturing. The 4 th line starts with the rev letter of the part.
For the form CN0481 Korea, the letter C would be the rev letter of the chip.