A high-performance asynchronous SCSI controller

We describe the design of a high performance asynchronous SCSI (Small Computer Systems Interface) controller data path and the associated control circuits. The data path is an asynchronous pipeline and the control circuits for the data path are built out of extended burst-mode machines [11]. This design is functionally compatible with a widely used commercial SCSI controller and was simulated correctly with respect to all of the applicable test vectors used for the commercial design. The technology used for this design is a 0.8 m CMOS standard cell. The performance is limited by the SCSI speci cation, not the design itself, and the area is competitive with the commercial design. This design improves the data transfer throughput by up to 2.5 times from previous work [7] by incorporating a FIFO and a distributed control scheme based on extended burst-mode state machines.