Memory system, memory device and command protocol

Abstract

A memory system, memory, and memory system command protocol are disclosed. Within the memory system, a memory controller communicates a command to the memory, the command being selected from a set of commands including a write command and a plurality of non-write commands. A Hamming distance value calculated between a digital value indicating the write command and a digital value indicating any one of the plurality of non-write commands is greater than 1.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This is a divisional of application Ser. No. 11 / 779,349 filed on Jul. 18, 2007, which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates generally to memory systems, memories, and command protocols for memory systems.[0004]2. Description of Related Art[0005]The concept of a “memory system” now encompasses a great variety of circuits and related control methods and protocols enabling the transfer, storage and retrieval of digital data. Once memory systems were associated with only computers systems and similar computational logic platforms. Now, a great host of consumer products ranging from cell phones to automobiles to refrigerators include memory systems of varying degrees of complexity.[0006]A generic memory system is conceptually illustrated in Figure (FIG.) 1, wherein a memory 2 stores data received from a memory controller 1 via a channel 3.[0007]A...

AI Technical Summary

Benefits of technology

[0023]In recognition of the competing demands placed upon memory system designers, embodiments of the invention provide a memory system command protocol that offers improved immunity to communication errors. This is particularly true in the context of “write commands.” In one aspect, the improved immunity of memory system commands within embodiments of the invention allows a reduction in the sophistication of EDC capabilities incorporated within the memory system, or the completion omission of EDC capabilities from the memory system. Alternately, given a defined set of EDC capabilities within a memory system, a command protocol consistent with embodiments of the invention results in a significant reduction in the likelihood of command misinterpretation and erroneous execution in an associated memory. As a further result, data integrity is assured and memory system reliability improved.

Problems solved by technology

Given the concurrent commercial motivations of reducing memory system size and power consumption while maximizing available data bandwidth and data throughput, it is not surprising that certain practical limitations and resource conflicts have been identified.

Unfortunately, increasingly fast clock speeds also increase the likelihood of data communication (transmission and / or reception) errors.

Indeed, system complexity has become so great and data transfer speeds so fast, that many contemporary memory systems now incorporate error detection and / or error correction (hereafter, singularly or collectively indicated as “EDC”) capabilities designed to mitigate the inevitable consequences of data communication errors.

While EDC capabilities offer great benefits in the verification of data being communicated between a memory controller and a memory, such capabilities come at a price.

EDC operations run in the memory controller, and more particularly, EDC operations run in the memory potentially generate a data throughput bottleneck in the memory system.

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