Patent ID: 8082481

Claim:
A computer program product for inserting multiple cyclic redundancy checks (CRCs) in an output data stream from a channel subsystem to a control unit of an input/output (I/O) processing system, the computer program product comprising: a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: receiving a message to transmit from the channel subsystem to the control unit via the output data stream; determining a first CRC insertion position in the output data stream; receiving a first CRC calculated over a first block of data in the message; inserting the first calculated CRC in the output data stream at the first CRC insertion position; determining a second CRC insertion position in the output data stream; receiving a second CRC calculated over a second block of data in the message; and inserting the second calculated CRC in the output data stream at the second CRC insertion position.