Patent ID: 6430632
Filing Date: 2002-08-06
Classification: G06F

Abstract:
A method of extending SCSI communications between at least two SCSI interfaces comprising the steps of:receiving SCSI signals from one of the at least two SCSI interfaces, parallel loading the SCSI signals from the one of the at least two SCSI interfaces into a parallel register, serializing the SCSI signals from the one of the at least two SCSI interfaces into serial data, transmitting the serial data derived from the parallel register over an optical communication system, converting the transmitted serial data back to the SCSI signals from the one of the at least two SCSI interfaces, shifting and receiving the SCSI signals from the one of the at least two SCSI interfaces into a data management and driver system; using the data management and driver system to manage and drive the SCSI signals from the one of the at least two SCSI interfaces to another of the at least two SCSI interfaces; receiving SCSI signals from the another of the at least two SCSI interfaces, parallel loading the SCSI signals from the another of the at least two SCSI interfaces into another parallel register, serializing the SCSI signals from the another of the at least two SCSI interfaces into serial data, transmitting the serial data derived from the another parallel register over another optical communication system, converting the transmitted serial data back to the SCSI signals from the another of the at least two SCSI interfaces, shifting and receiving the SCSI signals from the another of the at least two SCSI interfaces into another data management and driver system, and using the another data management and driver system to manage and drive the SCSI signals from the another of the at least two SCSI interfaces to the one of the at least two SCSI interfaces; wherein the step of shifting and receiving from the one of the at least two SCSI interfaces further comprises the steps of: receiving the SCSI signals from the one of the at least two SCSI interfaces, arbitrating between the SCSI signals as to which of the SCSI signals are to be transmitted to the another of the at least two SCSI interfaces, selecting a set of the SCSI signals that the one of the at least two SCSI interfaces will transmit to the another of the at least two SCSI interfaces, and driving the set of the SCSI signals from the one of the at least two SCSI interfaces to the another of the at least two interfaces; and wherein the arbitrating step further comprises the step of: receiving a bit from twenty seven bits of the converted back SCSI signals from the one of the at least two SCSI interfaces, determining whether the bit is equal to one and a bus value of the another of the at least two SCSI interfaces equals zero, driving the bus value to equal one if the bit is equal to one and the bus value is equal to zero, determining whether the bit is equal to zero and the bus value is equal to one if the bit is not equal to one and the bus value is not equal zero, stopping drive of the bus value to allow the bus value to equal zero if the bit is equal to zero and the bus value is equal to one, moving directly to determine if all of the twenty seven bits have been processed if the bit is equal to the bus value, determining if all of the twenty seven bits have been processed, obtaining a next bit and repeating the above steps if all of the twenty seven bits have not been processed, and determining whether a select has been activated to end the arbitrating step.