Abstract: The management of customer security keys by an integrated circuit manufacturer with automated material tracking among multiple circuit testers at multiple sites for programming keys into circuits. Limited key change methods plus sufficient key statuses provides processes for key handling.

Abstract: Methods and systems for programming secure data into programmable and irreversible memory cells included in electronic circuitry are provided. In general, the secure data is stored in one or more arrays integrated into or associated with an electronic device such as an IC. According to a disclosed method embodying the invention, a programmable and irreversible memory cell array has a control bit for indicating the program state of the array. The method includes reading the control bit of the array to identify a programmable state, loading and programming secure data, read-protecting and write-protecting the array. The control bit is programmed to indicate the non-programmable state of the programmed array.