Patent ID: 7913148

Claim:
An improved RAID disk array controller comprising: a plurality of serial disk drive interfaces for attaching physical disk drives to form a disk drive array; each of the serial disk drive interfaces including a separate buffer memory for storing write data to be stored on the attached physical disk drive in a disk write operation; each of the serial disk drive interfaces providing a status flag output to indicate when the associated buffer memory is FULL; switch logic circuitry coupled to all of the serial disk drive interfaces for receiving the write data from at least one DMA channel and providing the write data to the separate buffer memories during a write operation; a logic circuit for detecting when all of the separate buffer memories are not full; and a control circuit responsive to the logic circuit for synchronously writing the write data from the at least one DMA channel to all of the separate buffer memories via the switch logic circuitry, thereby forming synchronous write data; wherein the switch logic circuitry includes a boolean XOR circuit for forming redundant data “on the fly” from the synchronous write data for storing in the disk drive array; wherein the switch logic circuitry steers the redundant data to one or more of the serial disk drive interfaces for storage concurrently with the write data in a single disk write operation; wherein the boolean XOR circuit includes a disk write XOR circuit utilized for the disk write operation and a disk read XOR circuit utilized for a disk read operation.