The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 15, 1996
Filed:
Aug. 31, 1994
Carl L Ostrowski, Ann Arbor, MI (US);
Other;
Abstract
In a data processing system having a data processor coupled to a SCSI channel disposed for transmitting and receiving data between the data processor and a peripheral storage subsystem, a bridge controller for expanding the maximum allowable number of disk drives connectable to the SCSI channel. The bridge controller comprises a microprocessor having input/output terminals coupled to a CPU bus; a memory having input/output terminals coupled to a DMA bus; a buffer coupled between the CPU bus and the DMA bus; a first transceiver coupled between the DMA bus and the SCSI channel; a second transceiver coupled between the DMA bus and the disk drives; and, a circuit for controlling the direction of data flow through the buffer. The circuit has input/output terminals coupled to the CPU bus and a control output coupled to a direction control input terminal of the buffer. The circuit also includes a decoder for decoding the operation requested by the microprocessor and for granting a DMA bus request signal in response thereto; and, an arbitrator that arbitrates between DMA request signals from the microprocessor, the first transceiver or the second transceiver so that a DMA bus grant signal is granted to only one at a time.