International Business Machines Corporation

James A Yankosky

William Paul Hovis

John Edward Barth, Jr

Howard L Kalter

Scott C Lewis

Charles E Drake

Daniel J Nickel

John Atkinson Fifield

Robert E Busch

Endre P Thoma

Gordon A Kelley, Jr

Theodore M Redman

Charles H Stapper

A DRAM having on-chip ECC and both bit and word redundancy that have been optimized to support the on-chip ECC. The bit line redundancy features a switching network that provides an any-for-any substitution for the bit lines in the associated memory array. The word line redundancy is provided in a separate array section, and has been optimized to maximize signal while reducing soft errors. The array stores data in the form of error correction words (ECWs) on each word line. A first set of data lines (formed in a zig-zag pattern to minimize unequal capacitive loading on the underlying bit lines) are coupled to read out an ECW as well as the redundant bit lines. A second set of data lines receive the ECW as corrected by bit line redundancy, and a third set of data lines receive the ECW as corrected by the word line redundancy. The third set of data lines are coupled to the ECC block, which corrects errors encountered in the ECW. The ECC circuitry is optimized to reduce the access delays introduced by carrying out on-chip error correction. The ECC block provides both the corrected data bits and the check bits to an SRAM. Thus, the check bits can be externally accessed. At the same time, having a set of interrelated bits in the SRAM compensates for whatever access delays are introduced by the ECC. To maximize the efficiency of switching from mode to mode, the modes are set as a function of received address signals.

Dynamic RAM with on-chip ECC and optimized bit and word redundancy

A method and device for setting at least three operating modes of a memory device is provided. The voltage signal is sensed at a first input and an enable signal is sensed at a second input. When an enable signal is received at a second input the memory device operates at the first operating mode if the voltage state at the first input is low; it operates at a second mode if the voltage state at the second is high; and it operates at a third operating mode if the voltage at the first input changes after the enable signal is received at the input. Also a four mode operation can be achieved.

Multiple mode-set for IC chip

Low power addressing systems are provided which include a given number of memory segments, each having word and bit/sense lines, a given number of decoders coupled to the given number of memory segments for selecting one word line in each of the memory segments, a first plurality of transmission gate systems, each having first and second transmission gates, with each of the gates being coupled to a different one of the decoders, a second decoder having the first plurality of outputs, each of the outputs being coupled to a respective one of the transmission gate systems, first control circuits for selectively activating the first and second gates in each of the first plurality of transmission gate systems, a second given number of decoders coupled to the given number of memory segments for selecting one bit/sense line in each of the memory segments, a second plurality of transmission gate systems, each having first and second transmission gates, with each of the gates of the second plurality of transmission gate systems being coupled to a different one of the second given number of decoders, and second control circuits for selectively activating the first and second gates of each of the second plurality of transmission gate systems.

Low power addressing systems

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Essex Junction, VT, United States of America

James A Yankosky