Clifford A Petersen

US Patent:

52972763, Mar 22, 1994

Filed:

Dec 26, 1991

Appl. No.:

7/814389

Inventors:

James P. Millar - San Jose CA
Eddie B. Collins - San Jose CA
Ronald Weber - Sunnyvale CA
Clifford A. Petersen - San Jose CA

Assignee:

Amdahl Corporation - Sunnyvale CA

International Classification:

G06F 1100
G06F 1300

US Classification:

395550

Abstract:

Determinism is maintained in a synchronous first system although the first system receives behaviorchanging signals from a second system running asynchronously relative to the first system. The second system refrains from sending behavior-changing signals to the first system until the first system stops its clock at a prespecified clock cycle and signals the second system of the event. The second system then downloads the behavior-changing signals into the first system and restarts the first system clock. The first system awakens to discover that the behavior-changing signals have been received during the prespecified clock cycle. This is repeated over multiple runs, and in each run the same behavior-changing signals are transferred at the same prespecified clock cycles of the first system. Deterministic behavior is thereby maintained in the first system.