RECONFIGURABLE DUAL PROCESSOR SYSTEM

摘要

A dual processor system (100) with duplicated memory (114, 124) that has two modes (10, 11) of operation: a converged mode (10) in which one of the two processors (101, 102) is active and executing all tasks of the system while the other processor is inactive; and a diverged mode (11) in which both processors are active and executing substantially independently of each other different tasks of the system. The system automatically changes its modes of operation in response to requests such as manual and program control and certain system fault conditions. In the diverged mode, the system may be in either of two states of operation (1 and 2). In one state (1) one of the processors (101) is designated a primary processor, and in the other state (2) the other processor (102) is designated the primary processor. In the converged mode the system may be in either of four states of operation (3-6). In two of these states (3, 4) one of the processors is active while the other processor is standing by ready to take up execution of tasks from the point where the one processor stopped execution. In the other two of these states (5, 6) one of the processors is active while the other processor is out of service and cannot take up task execution without being initialized. The system (100) makes transitions between the various states in response to requests. Except for transitions of an active processor to an out-of-service condition, the state transitions are transparent to tasks other than fault recovery programs and, upon a fault condition, the faulted program.