International Business Machines Corporation

Michael P Clinton

Mark William Kellogg

Wilbur David Pricer

Erik L Hedberg

Timothy Jay Dell

Russell J Houghton

Marc Raymond Faucher

Duane E Galbi

Alan D Norris

Josef T Schnell

Klaus G F Enk

Apparatus and method for performing a defect leakage screen test for memory devices

A high speed Random Access Memory (RAM) array device includes several logical banks, each of which can be uniquely addressed. Each of these logical banks contains a unique memory array segment and associated page register, the latter serving as a temporary storage location during high-speed page hit operations. To reduce latency during an initial page hit, further array optimization is realized by segmenting each logical bank into two segments with one, smaller segment, comprising a faster random access memory (FRAM) for storing initial data in a data stream. A high speed page register connects the FRAM directly to a multiplexer/demultiplexer connected to the device I/O ports bypassing an internal bus protocol such that the initial data can be transferred between the FRAM and the I/O ports faster thereby improving page-hit latency. Hence, segmenting the logical banks to include only a small high speed segment results in a performance gain approaching what could be achieved by implementing the entire memory device with a high speed FRAM, but at much lower cost.

Narrow data width DRAM with low latency page-hit operations

A high speed/narrow I/O DRAM device comprises both a data input/output (I/O) port as well as a command port for receiving commands used to control the operations of the DRAM. The command port is defined as input only (i.e., for inputting command data). The present invention comprises multiplexing write data to be written and stored in the DRAM onto the command port with command data packets. The data I/O port can then become dedicated to streaming out seamless data since it no longer needs to flip between input and output data. Even greater bus efficiency can be realized if, during a command packet transfer, data writes to the DRAM are switched back to the data I/O port. With this input port switching protocol, greater bus efficiency and increased memory performance can be realized.

Input port switching protocol for a random access memory

A semiconductor memory chip architecture is described implementing of a multi-bit data control function which enables independent control of at least a plurality of data bits via a single control signal. A logically organized memory chip is organized as a 2.sup.n x 4 chip in which one control (CAS0) signal enables a single data bit and another control (CAS1) signal enables the remaining three data bits. By organizing data control on chips in this manner, it becomes possible to optimize design modules such that a minimum number of control signals are used.

Memory device having asymmetrical CAS to data input/output mapping and

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Michael P Clinton