International Business Machines Corporation

Michael R Nelms

Kevin William Gorman

Jeffrey H Dreibelbis

Darren Lane Anand

Disclosed is a method for segmenting functionality of a hybrid built-in self test (BIST) architecture for embedded memory arrays into remote lower-speed executable instructions and local higher-speed executable instructions. A standalone BIST logic controller operates at a lower frequency and communicates with a plurality of embedded memory arrays using a BIST instruction set. A block of higher-speed test logic is incorporated into each embedded memory array under test and locally processes BIST instructions received from the standalone BIST logic controller at a higher frequency. The higher-speed test logic includes a multiplier for increasing the frequency of the BIST instructions from the lower frequency to the higher frequency. The standalone BIST logic controller enables a plurality of higher-speed test logic structures in a plurality of embedded memory arrays.

Method for segmenting BIST functionality in an embedded memory array into remote lower-speed executable instructions and local higher-speed executable instructions

A bit fail map circuit accurately generates a bit fail map of an embedded memory such as a DRAM by utilizing a high speed multiplied clock generated from a low-speed Automated Test Equipment (ATE) tester. The circuit communicates between the ATE tester, the embedded memory under test, Built-In Self-Test (BIST) and Built-In Redundancy Analysis (BIRA). An accurate bit fail map of an embedded DRAM memory is provided by pausing the BIST test circuitry at a point when a fail is encountered, namely a mismatch between BIST expected data and the actual data read from the array, and then shifting the bit fail data off the chip using the low-speed ATE tester clock. Thereafter, the high-speed test is resumed from point of fail by again running the BIST using the high-speed internal clock, to provide at-speed bit Fail Maps.

Automatic bit fail mapping for embedded memories with clock multipliers

Disclosed is a hybrid built-in self test (BIST) architecture for embedded memory arrays that segments BIST functionality into remote lower-speed executable instructions and local higher-speed executable instructions. A standalone BIST logic controller operates at a lower frequency and communicates with a plurality of embedded memory arrays using a BIST instruction set. A block of higher-speed test logic is incorporated into each embedded memory array under test and locally processes BIST instructions received from the standalone BIST logic controller at a higher frequency. The higher-speed test logic includes a multiplier for increasing the frequency of the BIST instructions from the lower frequency to the higher frequency. The standalone BIST logic controller enables a plurality of higher-speed test logic structures in a plurality of embedded memory arrays.

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Williston, VT, United States of America

Michael R Nelms