King H Mak

US Patent:

46601708, Apr 21, 1987

Filed:

Apr 29, 1985

Appl. No.:

6/728621

Inventors:

Kenneth H. Hui - Duarte CA
King C. Mak - Alhambra CA
David G. Hardesty - San Dimas CA

Assignee:

General Dynamics, Pomona Division - Pomona CA

International Classification:

G06F 100

US Classification:

364900

Abstract:

A system for providing information to alter the software of an electronic data processor embedded in an electronic module includes a remote reprogramming module that conducts a sequence of operations to provide data to the processor which the processor uses to reprogram itself. The system employs a data link having a bi-directional transmission path connecting the processor and the reprogramming module. A controlled switching circuit is provided at each end of the transmission path. Under normal operating conditions, the transmission path is used to transit a function signal for a function performed by the electronic module. Periodically, the processor operates one switching network to capture the path for transmission of a reprogramming inquiry signal to the reprogramming module. At the same time, the function signal is diverted to an alternate path internal to the electronic module. When the reprogramming module detects a reprogramming inquiry, it operates the other switching circuit to gain access to the transmission path.