Micron Technology Incorporated

Other

Ken Waller

Warren M Farnworth

Brent Keeth

Troy A Manning

Eugene H Cloud

Leland R Nevill

Paul S Zagar

Ray J Beffa

Adrian E Ong

Adrian H Ong

A test arrangement for a memory device wherein the equilibration voltage DVC2 is adjusted up or down relative to a nominal value and coupled to one of the bitlines of the paired bitlines of the memory array, while the equilibrating circuit is held disabled, and then the sense amplifiers are used to pull the bitlines to logic 1 and logic 0 levels initializing the bitlines to test data. Appropriate word lines are fired to copy the test data to some or all of the other rows of the memory array, allowing memory tests to be conducted. In another embodiment, a fixed voltage is applied to one of the bitlines of individual bitlines pairs and the sense amplifiers are used to pull the paired bitlines to the correct voltage. In a further embodiment, fixed voltages Vcc and ground are applied to the bitlines of each bitline pair with the sense amplifier being held disabled. The test arrangement can be implemented as a self-test feature for the memory device.

Test arrangement for memory devices using a dynamic row for creating

A method of testing a memory array is disclosed, the method comprising writing a test pattern to the memory array in as few as one or two RAS cycles by first activating the input/output data lines and then selectively activating multiple rows and columns. The method can be used with a variety of test environments. For example, the disclosed method may be implemented in testing using automated test equipment, and may also be incorporated in devices having built-in self-test circuitry. The disclosed method reduces the time required to test the memory array with minimal additional circuitry and no encroachment on valuable die real estate.

Test method and apparatus for writing a memory array with a reduced

A semiconductor dynamic random-access memory (DRAM) device embodying numerous features that collectively and/or individually prove beneficial and advantageous with regard to such considerations as density, power consumption, speed, and redundancyis disclosed. The device is a 64 Mbit DRAM comprising eight substantially identical 8 Mbit partial array blocks (PABs), each pair of PABs comprising a 16 Mbit quadrant of the device. Between the top two quadrants and between the bottom two quadrants are column blocks containing I/O read/write circuitry, column redundancy fuses, and column decode circuitry. Column select lines originate from the column blocks and extend right and left across the width of each quadrant. Each PAB comprises eight substantially identical 1Mbit sub-array blocks (SABs). Associated with each SAB are a plurality of local row decoder circuits functioning to receive partially decoded row addresses from a column predecoder circuit and generating local row addresses supplied to the SAB with which they are associated. A hierarchical data path is provided wherein a plurality of multiplexers are distributed throughout each SAB, these multiplexers functioning to selectively couple sense amplifier output signals to local data I/O lines associated with each SAB. In one embodiment, the data path multiplexers are physically disposed within gaps defined by adjacent ones of the local row address decoders distributed throughout each SAB.

Dynamic random-access memory having a hierarchical data path

A semiconductor dynamic random-access memory (DRAM) device embodying numerous features that collectively and/or individually prove beneficial and advantageous with regard to such considerations as density, power consumption, speed, and redundancy is disclosed. The device is a 64 Mbit DRAM comprising eight substantially identical 8 Mbit partial array blocks (PABs), each pair of PABs comprising a 16 Mbit quadrant of the device. Between the top two quadrants and between the bottom two quadrants are column blocks containing I/O read/write circuitry, column redundancy fuses, and column decode circuitry. Column select lines originate from the column blocks and extend right and left across the width of each quadrant. Each PAB comprises eight substantially identical 1 Mbit sub-array blocks (SABs). Associated with each SAB are a plurality of local row decoder circuits functioning to receive partially decoded row addresses from a column predecoder circuit and generating local row addresses supplied to the SAB with which they are associated. Various pre- and/or post-packaging options are provided for enabling a large degree of versatility, redundancy, and economy of design. Programmable options of the disclosed device are programmable by means of both laser fuses and electrical fuses. In the RAS chain, circuitry is provided for simulating the RC time constant behavior of word lines and digit lines during memory accesses, such that memory access cycle time can be optimized. Test data compression circuitry optimizes the process of testing each cell in the array. On-chip topology circuitry simplifies the testing of the device.

Dynamic random access memory having decoding circuitry for partial

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Boise, ID, United States of America

Ken Waller