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:
Jun. 04, 1996
Filed:
Apr. 21, 1993
Hironao Sone, Yokohama, JP;
Kazuo Sekiya, Tokyo, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
To enable wired-OR signal lines to be connected without interlock in a bus linkage unit for connecting the bus of a computer system with the bus of an expansion device or the bus of another computer system through a signal transfer path in which the signal mode is different from those of the buses. A shadow register 46 that acts on the level of wired-OR signal line 51 of the other bus is provided in each system. The level of wired-OR signal lines in each system is sent to the shadow register of the other system through a communication path. When the shadow register of the system is at a predetermined level, said system will not send the level of said wired-OR signal line to the other system. Interlock is eliminated by avoiding repetition of level transfer echoes between both systems in this way. Both systems are further provided with a shadow-shadow register 47 for forming a mirror image of the shadow register of the other system. A predetermined level will be sent to the shadow register of the other system based on the nonconformity between the level of the shadow-shadow register in each system and the level of wired-OR signal line of said system.