Disclosed is a host adapter having automatic termination, and a method for implementing the automatic termination. The host adapter includes a first connector for connecting to at least one external peripheral device and a second connector for connecting to at least one internal peripheral device. The host adapter further includes a termination system circuit that is coupled between the first connector and the second connector. The termination system circuit is configured to produce bit data that is indicative of whether a peripheral device is coupled to one or both of the first connector and the second connector. Preferably, the termination system circuit communicates the bit data to a software termination engine upon boot-up to enable or disable a termination of the host adapter. Furthermore, the termination system circuit includes a termination control decoder and a tri-state buffer. The host adapter also includes a termination over-ride control that is configured to over-ride the automatic termination generated by the termination system circuit via a software control.
Methods Of And Apparatus For Monitoring The Termination Status Of A Scsi Bus
When more than two terminators are on a SCSI bus the bus is said to be "over-terminated", and when less than two terminators are on the bus, the bus is said to be "under-terminated". When the SCSI bus is either under or over terminated, the bus does not function, and often the user does not know why the bus is not functioning. Apparatus and a method are provided for indicating to the user when the bus is not properly terminated. A terminator monitoring system and method operate in conjunction with the bus. A precision resistor is connectable to the bus so that a voltage drop is produced across the precision resistor. A circuit monitors the value of the produced voltage drop across the precision resistor to provide an indication of the number of terminators on the bus. A switch selectably connects the precision resistor to the bus, and there is a source of a reference voltage. The monitoring circuit includes a comparison circuit responsive to the voltage drop across the precision resistor and to the reference voltage for indicating whether the number of terminators on the bus exceeds a limit or is less than the limit.
Scsi Bus Transceiver And Method For Making The Same
Abdul Waheed Mohammed - Sunnyvale CA Peter K. Cheung - Milpitas CA Barry Davis - Union City CA Christopher Burns - San Jose CA
Assignee:
Adaptec, Inc - Milpitas CA
International Classification:
G06F 1300
US Classification:
710 62
Abstract:
Disclosed is a SCSI host adapter for use in a computer system. The SCSI host adapter is configured to provide the computer system with interconnection with internal and/or external target devices. The SCSI host adapter includes a low voltage differential connector for interconnecting to a low voltage differential bus, and the low voltage differential bus is configured to communicate a first transaction. The SCSI host adapter also includes a single ended connector for interconnecting to a single ended bus, and the single ended bus is configured to communicate a second transaction. Furthermore, the SCSI host adapter includes a transceiver unit that is configured to interface between the low voltage differential bus and the single ended bus and produce a target information signal. The target information signal is configured to indicate whether the first transaction or the second transaction is occurring between the SCSI host adapter and the low voltage differential bus or the single ended bus.
Dr. Cheung graduated from the New York University School of Medicine in 1997. He works in Temple, TX and specializes in Cardiovascular Disease and Clinical Cardiac Electrophysiology. Dr. Cheung is affiliated with Baylor Scott & White Health Memorial Hospital-Temple and Scott & White Hospital Round Rock.
Dr. Cheung graduated from the Saint Louis University School of Medicine in 1982. He works in Manchester, NH and 1 other location and specializes in Nephrology. Dr. Cheung is affiliated with Catholic Medical Center, Concord Hospital and Elliot Hospital.
Dr. Cheung graduated from the Oral Roberts University School of Medicine at Tulsa in 1989. He works in Yuma, AZ and specializes in General Surgery and Vascular Surgery. Dr. Cheung is affiliated with Yuma Regional Medical Center.