摘要 |
A method and apparatus for performing XOR operations on a hard disk drive are provided, which optimize the buffer bandwidth with minimal logic added to the hard disk controller integrated circuit. This is achieved by first storing data from a first source in the buffer memory in an interleaved fashion (i.e. at memory locations having addresses k, k+2 . . . ,k+2n-2) and then sequentially reading each bit set from the buffer memory, XORing it with a corresponding bit set read from a second source and writing the result at the next consecutive location in the buffer memory (i.e. at memory locations having addresses k+1, k+3 . . . k+2n-1). The method can be implemented on existing hard disk controllers with minimal modifications to the hardware. In addition, an embodiment of the invention allows for decoupling of the XOR operation from disk and host transfers, allowing each of those transfers to occur at their maximum rate and using the remaining buffer bandwidth for the XOR operation.
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