Western Digital Technologies, Inc.

Ming-Yu Tai

Haining Liu

Yun-Tzuo Lai

YungLi Ji

Yung-Li Ji

Subhash Balakrishna Pillai

Systems and methods are disclosed for scheduling access commands for a data storage device. A data storage device determines a layout of a plurality of non-volatile memory arrays. The data storage device also determine completed access statistics and pending access statistics for a first set of the plurality of non-volatile memory arrays during a monitoring period. The data storage device further generates a schedule based on the layout of the plurality of non-volatile memory arrays, the completed access statistics, and the pending access statistics and executes access commands based on schedule.

Scheduling access commands for data storage devices

A method of wear leveling receives a write request. The write request indicates received data to be written to memory blocks. The method detects a system condition. Example system conditions include a random write condition, a garbage collection start condition, and/or a sequential write condition. Based on the system condition, the method determines whether the received data comprises hot data or cold data. Some embodiments use a write amplification value to determine the system condition. If the received data comprises hot data, the method writes the received data to a cold block. If the received data comprises cold data, the method writes the received data to a hot block.

Memory apparatus and methods thereof for write amplification aware wear leveling

A device that provides garbage collection read throttling includes at least one processor that is configured to receive a request to perform a garbage collection read command on one of a plurality of flash memory circuits. The at least one processor is configured to determine whether garbage collection read throttling is enabled, such as when a garbage collection read throttling criterion is satisfied. The at least one processor is configured to buffer the garbage collection read command when garbage collection read throttling is enabled and perform the garbage collection read command when garbage collection read throttling is disabled. When the garbage collection read throttling is enabled and the garbage collection read command is buffered, the at least one processor is configured to perform the buffered garbage collection read command when garbage collection read throttling is subsequently disabled.

Garbage collection read throttling

A method, system, and apparatus are provided for retiring computer memory blocks. Two overall schemes are provided for separating poorly functioning blocks from normally functioning blocks. In a first scheme, after data relocation is finished, firmware remembers the old physical memory block. As soon as the system writes to the old physical memory block with new data, firmware issues a read again and receives back a count of error bits. If the returned error bits are still high, then the system identifies the block as being weak and retires the block. In a second scheme, firmware tracks statistics for data relocates, block reads, activity timers, among other statistics. If some blocks have abnormal activities (e.g., too many data relocates, too many reads, etc.), then the system may identify the block as being weak and may retire the physical memory block.

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Irvine, CA, United States of America

Ming-Yu Tai