System and method for generating 128-bit cyclic redundancy check values with 32-bit granularity

A system for generating CRC values in a Data Transmission System having a data bus adapted for handling a plurality of data blocks in parallel, said plurality of data blocks comprising a data segment, said system comprising:

• a) a memory for storing data blocks, said memory adapted to output a plurality of data blocks simultaneously;
• b) a data bus, coupled to said memory, said data bus providing a data path wide enough to accommodate said plurality of data blocks;
• c) a plurality of CRC cores coupled to said data bus;
• and
• d) a first multiplexer coupled to said CRC cores for selecting the output of one of said CRC cores based on a number of data blocks output on said data bus;
• wherein a data segment is transmitted using an Internet small computer system interface (iSCSI) protocol;
• wherein CRC values are calculated in accordance with a predetermined algorithm that accommodates said data segment transmitted using said iSCSI protocol, utilizing transport offload engine (TOE) including a physical data link that provides a physical connection to the Internet, a network stack in communication with said physical data link utilizing a TCP/IP protocol, a storage protocol services processor in communication with said network stack for exchanging data with said network stack, processing requests from a storage application, and encapsulating or decoding packets as requested by said storage application in accordance with said iSCSI protocol.

A circuit for calculating CRC values comprising:

• a) a memory for storing data blocks, said memory including a plurality of outputs for simultaneously outputting data segments having a plurality of data blocks;
• b) a data bus, coupled to said memory, said data bus having a data path for each of said data blocks;
• c) a plurality of registers coupled to said data bus, said registers for temporarily storing data blocks within a data segment output from said memory, wherein said registers are adapted for storing any combination of data blocks within said data segment;
• d) a plurality of CRC cores coupled to each of said respective registers, said CRC cores for calculating CRC values for said data blocks stored in each of said registers;
• and
• e) a multiplexer for selecting a CRC value calculated by one of said CRC cores, based on which of said plurality of registers contain valid data;
• wherein said data segment is transmitted using an Internet small computer system interface (iSCSI) protocol;
• wherein a plurality of CRC values are calculated in accordance with a predetermined algorithm that accommodates said data segment transmitted using said iSCSI protocol, utilizing a transport offload engine (TOE) including a physical data link that provides a physical connection to the Internet, a network stack in communication with said physical data link utilizing a TCP/IP protocol, a storage protocol services processor in communication with said network stack for exchanging data with said network stack, processing requests from a storage application, and encapsulating or decoding packets as requested by said storage application in accordance with said iSCSI protocol.

A method for calculating cyclical redundancy check (CRC) values, comprising:

• receiving data;
• calculating a CRC value in accordance with a predetermined algorithm that accommodates an Internet small computer system interface (iSCSI) protocol, utilizing a transport offload engine (TOE) including a physical data link that provides a physical connection to the Internet, a network stack in communication with said physical data link utilizing a TCP/IP protocol, a storage protocol services processor in communication with said network stack for exchanging data with said network stack, processing requests from a storage application, and encapsulating or decoding packets as requested by said storage application in accordance with said SCSI protocol;
• appending said CRC value to said data;
• and
• transmitting said data utilizing said iSCSI protocol.