XOR controller for a storage subsystem
July 20, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesBuffer for use with a fixed disk controller Disk drive controller Disk drive system controller architecture Disk drive controller system with enhanced communications interface Disk drive controller system Methods and apparatus for fault detection Direct access storage device with independently stored parity Disk drive controller system Data processing system emulation in a window with a coprocessor and I/O emulation Data redundancy and recovery protection InventorsAssigneeApplicationNo. 278870 filed on 07/20/1994US Classes:714/5, Of memory or peripheral subsystem714/759, Look-up table encoding or decoding714/801Parity generator or checker circuit detailExaminersPrimary: Beausoliel, Robert W. Jr.Assistant: Wright, Norman M. Attorney, Agent or FirmInternational ClassesG06F 011/00H03M 013/00 AbstractAn XOR controller which is capable of performing the XOR operations necessary to generate a new parity value corresponding to new data being written to a disk storage device from a host computer without the intervention of the storage subsystem microprocessor. In one embodiment the storage subsystem microprocessor controls the loading of the new data from the host and old data and parity from a disk storage device into cache memory, if such data is not already in cache memory, and creates the appropriate data structures. The storage subsystem microprocessor then loads the XOR controller with a pointer to a table in cache memory containing information needed by the XOR controller to perform the XOR operations. The XOR controller, upon completion of the XOR operations on all the data, informs the storage subsystem microprocessor of such completion. Thereafter, the microprocessor causes the new data and new parity to be written to the disk storage device from the cache memory. | |
