{PDF} SCSI-3 Fast-20 (F20 r06) T10 Technical Committee

This standard defines the mechanical, electrical, and timing requirements of the SCSI-3 Fast-20 Transfer Protocol to allow conforming devices to inter-operate at the data transport level. Fast-20 only defines those requirements to support the Fast-20 data transfer rate using synchronous data transfers. Other requirements (e.g., connectors, asynchronous transfer timing, etc.) are defined in the SCSI-3 Parallel Interface (SPI). The mechanical, electrical, and timing requirements defined herein take precedence over those defined in SPI.