Infineon Technologies Ag

International Business Machines Corporation

Thomas Boehler

Gunther Lehmann

Li Ming Wang

Vasudev Dasappa

Juei Lung Chen

A modular test controller with a built-in self-test (BIST) circuit for testing an embedded DRAM (eDRAM) circuit is provided. The test controller includes a built-in self-test (BIST) core for performing tests, the BIST core including proven testing algorithms; a selectable tester interface for interfacing the BIST core with an external tester; and a selectable eDRAM interface for interfacing the BIST core with an eDRAM, the eDRAM including a plurality of memory cells for storing data. The present invention allows semiconductor device designers to keep to one testflow and reuse a proven BIST core over multiple ASIC (Application Specific Integrated Circuits) products/generations.

Modular test controller with BIST circuit for testing embedded DRAM circuits

A circuit and method for testing an eDRAM through a test controller with direct access (DA) mode logic is provided. The circuit and method of the present invention allows the testing of eDRAMs with a conventional memory tester. The present invention provides a semiconductor device including an embedded dynamic random access memory (eDRAM) for storing data, the eDram including a plurality of memory cells, and a test controller for testing the plurality of memory cells to determine if the cells are defective, the test controller including built-in self-test (BIST) logic circuitry for performing tests and for interfacing to a logic tester, and direct access mode logic circuitry for interfacing the eDRAM with an external memory tester. The test controller further comprises a multiplexer for multiplexing data, commands, and addresses from the BIST logic circuitry and the direct access mode logic circuitry to the eDRAM.

Circuit and method for testing embedded DRAM circuits through direct access mode

External test equipment is used to simulate an internal BIST test, thus enabling the capture or generation of detailed test results. By simulating the BIST test sequence in real time during the test, the external tester may monitor an output from the BIST and determine the exact location of failures when they occur. The external tester may generate a bit fail map indicating whether each memory location passed or failed the BIST test.

Built-in self test system and method

A memory apparatus is configured by obtaining test information for each of group of memory locations within the memory apparatus, compressing the test information to produced compressed test information and, based on the compressed test information, replacing a group of redundant memory circuits respectively associated with the group of memory locations.

Using data compression for faster testing of embedded memory

A precharge command can be issued to a single bank or a precharge-all command can be issued to all banks of an integrated circuit memory device (e.g., DRAM circuit) at any time during normal operation of the device. Internal circuits are provided to decode the respective commands and send them to the different independent memory banks of the integrated circuit memory device. A local precharge control unit (or circuit) is present inside each of the memory banks that can receive and process the decoded precharge commands. If certain specified timing conditions are met, the local precharge control unit can issue and store a precharge request for a specific bank. The precharge request can be held back until all timing requirements are fulfilled. The precharge request can then be automatically executed.

Systems and methods for executing precharge commands using posted precharge in integrated circuit memory devices with memory banks each including local precharge control circuits

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Ottobrunn, Germany

Thomas Boehler