Programmable multi-mode built-in self-test and self-repair structure for embedded memory arrays

摘要

A built-in self-test and self-repair structure (BISR) of memory arrays embedded in an integrated device, including at least a test block (BIST) programmable to execute on a respective memory array of the device any of a certain number of predefined test algorithms, and a self-repair block that includes a column address generator processing the faulty addresses information for allocating redundant resources of the tested memory array, a redundancy register on which final redundancy information are loaded at each power-on of the device and a control logic for managing data transfer from external circuitry to the built-in self-test and self-repair structure (BISR) and vice versa, utilizes a single built-in self-test (BIST) structure serves any number of embedded memory arrays even of different type and size. The built-in self-test and self-repair (BISR) structure further includes nonvolatile storage means containing information on addresses and data bus sizes of the device architecture, aspect ratio, capacity, multiplexing and scrambling parameters and relative test algorithm instructions for each of said embedded memory arrays and on which redundance column addresses are permanently stored and a multiple frequency clock generator for selecting the maximum operating clock frequency of the type of embedded memory array to be accessed. Two distinct selectable test flows of an embedded random access memory array are selectable by programming. A first two-step test flow, each step of which includes the execution of a complete BIST check on the array, and a second three-step test flow, each step of which includes the execution of a complete BIST check on the array, the third BIST check revealing a possible failed programming of the redundance column addresses in said nonvolatile storage means.