Multiple access unit for external memory unit

Abstract

Abstract PURPOSE: To make it possible to back up a system on occurrence of a fault of a controller by eliminating the latency time of controllers, by connecting drivers to the controllers. CONSTITUTION: When access from CPU1-2 to driver 3 -1-2 should be attained while CPU1-1 is in process of access to driver 3 -1-1 via input port 1 1-1 and output port 0 1-1 of controller 2-1 and connection cable C 5 , CPU1-2 attains access to driver 3 1-2 via input port 1 2-1 and output port 0 2-1 of controller 2-2 and connection cable C 12 after making sure that while controller 2-1 is exclusively used by CPU1-1, controller 2-2 is standing by. Similarly, access to the same driver is attained via a different controller when CPU judges that either controller 2-1 or 2-2 is in trouble. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Yoshio Hirota

Bibliographic Details