Bull Hn Information Systems, Inc.

Nec Corporation

Zenith Data Systems Corporation

Packard Bell Nec

Jeffrey S Somers

Chester M Nibby, Jr

Michelle A Pence

Thomas F Joyce

Jian-Kuo Shen

Bruno DiPlacido, Jr

Thomas L Murray, Jr

James F Bertone

G Lewis Steiner

Martin Massucci

Marc Sanfacon

Lance J McNally

Raymond D Bowden, Iii

Marc E Sanfacon

William S Wu

Suresh K Marisetty

Norman J Rasmussen

Puthiya K Nizar

Edward R Salas

George J Barlow

Richard A Lemay

Lance T McNally

Lewis G Steiner

Bruno Diplacido

Lance Mcnally

The invention is directed to a memory controller for use with memory having varying timing characteristics. In particular, the timing characteristics of the various memory devices are determined and used to generate timing signals commensurate with each particular memory device.

Symmetric multiprocessing system with unified environment and distributed system functions

A symmetric multiprocessing system with a unified environment and distributed system functions provides unified address space for all functional units in the system while distributing the execution of various system functions over the functional units of the system whereby each functional unit assumes responsibility for its own aspects of these operations. In addition, the system provides improved system bus operation for transfer of data from memory.

Symmetric multiprocessing system with unified environment and

Timing calculator means in a computer system are used to adaptively generate an appropriate access signal, to one of a plurality of memory types, based on first and second timing control values, wherein the first timing control value represents information specific to and limited to the start of a memory operation and wherein the second timing control value represents information representing other timing events. That is, the state machine of the present invention requires a distinct starting control value, separate from other timing values, for calculation of appropriate memory access parameters.

Adaptively generating timing signals for access to various memory

A memory system tightly couples to a high performance microprocessor through a synchronous bus. The logic circuits included in the memory system generate a blipper pulse signal using successive transitions of clock pulse signals other than the edges used to synchronize microprocessor and memory operations. The blipper pulse signal is logically combined with the memory's column address strobe timing signal which is derived from the synchronizing edges of clock pulse signals which defines the duration of the column address interval required for accessing of a pair of DRAM memories during successive memory cycles for providing sequences of four memory read responses with no wait state.

High performance burst read data transfer operation

A method and apparatus for resetting memory state when power is applied to the system. The memory has memory elements, a refresh clock and a refresh counter for counting refresh cycles and providing refresh signals to the memory elements, the memory elements and refresh means being connected from the power system and from a battery back-up means. A state detection means is connected from the refresh counter for detecting a change in state of the refresh counter to a state equivalent to the reset state of the refresh counter and asserting a state change signal. A means responsive to the state change signal and to the occurrence of the reset signal provides a memory controller reset signal, so that the memory controller reset signal occurs in synchronization with the change of state of the refresh counter to a state equivalent to the refresh counter reset state. The memory reset further includes a time-out counter means responsive to the assertion of the reset signal and to the refresh clock for counting refresh cycles in synchronization with the refresh counter. A time-out detection means is responsive to the time out counter means for providing a time out signal when the time-out counter has counted a refresh period plus one clock cycle and to the state change signal for providing the memory controller reset signal when the time-out counter has counted a refresh cycle plus one clock period and the state change signal has not been asserted.

Method and apparatus for resetting a memory upon power recovery

In accordance with the present invention, there is provided a system for logging an error that occurred in a multi-chip memory storage device in a data processing system. The system has a mechanism for detecting an error and for receiving data and check bits associated therewith. The mechanism for detecting an error generates syndrome bits as a function of the data and of the check bits. Connected to the error detecting mechanism is an error logging mechanism which is adapted to receive the syndrome bits and to determine the chip in which the error occurred.

Memory controller with error logging

A system and method for detecting an error that occurred in a multi-chip memory storage device in a data processing system. The system detects an error and receives data and check bits associated therewith. A process that uses the principle of scrubbing and incorporates high speed error flags distinguishes between hard and soft errors.

System for determining status of errors in a memory subsystem

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Lowell, MA, United States of America

Jeffrey S Somers