Method, circuit and apparatus for preserving and/or correcting product engineering information

Abstract

A method, circuit and apparatus is provided for preserving and/or correcting product engineering information. Non-volatile storage devices reserved for receiving product engineering bits can either be contained in at least three separate storage locations spaced from each other across the integrated circuit or, alternatively, be contained in a single storage location area with error correction bits and/or words added to that location. In the first instance, redundant product engineering bits are written to each storage location. Product engineering bits read from a majority of those locations which have identical values are deemed valid. The addition of extra bits and/or words can be combined with the possibly defective product engineering bits to correct errors in those bits. Using redundancy to correct errors caused by charge loss or charge gain within previously stored product engineering values proves a beneficial outcome since testing the product engineering bit locations is not necessarily a viable solution. The product engineering bit locations may be programmed well before test patterns can be written to and read from those locations. Further, the uniquely programmed product engineering bits may unduly be lost during normal assembly of die into an integrated circuit package.