2845 results about "Data error" patented technology

A storage subsystem is disclosed that maintains (a) statistics regarding errors detected via an ECC (error correction code) module of the storage subsystem; and / or (b) historical data regarding operating conditions experienced by the storage subsystem, such as temperature, altitude, humidity, shock, and / or input voltage level. The storage subsystem, and / or a host system to which the storage subsystem attaches, may analyze the stored data to assess a risk of a failure event such as an uncorrectable data error. The results of this analysis may be displayed via a user interface of the host system, and / or may be used to automatically take a precautionary action such as transmitting an alert message or changing a mode of operation of the storage subsystem.

A storage subsystem monitors one or more conditions related to the probability of a data error occurring. Based on the monitored condition or conditions, the storage subsystem adjusts an error correction setting, and thus the quantity of ECC data used to protect data received from a host system. To enable blocks of data to be properly checked when read from memory, the storage subsystem stores ECC metadata indicating the particular error correction setting used to store particular blocks of data. The storage subsystem may be in the form of a solid-state non-volatile memory card or drive that attaches to the host system.

A non-volatile storage subsystem maintains, and makes available to a host system, monitor data reflective of a likelihood of a data error occurring. The monitor data may, for example, include usage statistics and / or sensor data. The storage subsystem transfers the monitor data to the host system over a signal interface that is separate from the signal interface used for standard storage operations. This interface may be implemented using otherwise unused pins / signal lines of a standard connector, such as a CompactFlash or SATA connector. Special hardware may be provided in the storage subsystem and host system for transferring the monitor data over these signal lines, so that the transfers occur with little or no need for host-software intervention. The disclosed design reduces or eliminates the need for host software that uses non-standard or “vendor-specific” commands to retrieve the monitor data.

In a non-volatile memory, the displacement current generated in non-selected word lines that results when the voltage levels on an array's bit lines are changed can result in disturbs. Techniques for reducing these currents are presented. In a first aspect, the number of cells being simultaneously programmed on a word line is reduced. In a non-volatile memory where an array of memory cells is composed of a number of units, and the units are combined into planes that share common word lines, the simultaneous programming of units within the same plane is avoided. Multiple units may be programmed in parallel, but these are arranged to be in separate planes. This is done by selecting the number of units to be programmed in parallel and their order such that all the units programmed together are from distinct planes, by comparing the units to be programmed to see if any are from the same plane, or a combination of these. In a second, complementary aspect, the rate at which the voltage levels on the bit lines are changed is adjustable. By monitoring the frequency of disturbs, or based upon the device's application, the rate at which the bit line drivers change the bit line voltage can be adjusted. This can be implemented by setting the rate externally, or by the controller based upon device performance and the amount of data error being generated.

A system and technique for detecting data errors in a memory device. More specifically, data errors in a memory device are detected by initiating an internal READ command or cleansing operation from a set of logic which is internal to the memory system in which the memory devices reside. Rather than relying on a READ command to be issued from an external device, via a host controller, the cleansing logic initiates a cleansing routine in response to an event such as an operator instruction or a periodic schedule. By implementing the cleansing operation, the system does not rely on external READ commands to verify data integrity. Further, a monitoring device is coupled between the cleansing logic and a memory scheduler. The monitoring device provides a feed back mechanism from which to vary the frequency of certain memory requests such as the cleansing and scrubbing operations. The cleansing routine may rely on typical ECC error logging mechanisms and may be used in a RAID memory architecture. Further, the cleansing routine may be used in conjunction with other error logging and correction logic, as well as scrubbing logic.