Andrew C Pindar

US Patent:

51704706, Dec 8, 1992

Filed:

May 2, 1988

Appl. No.:

7/189062

Inventors:

Andrew Pindar - Sunnyvale CA
Duane Marcroft - San Carlos CA
Andrew J. Nichols - Palo Alto CA

Assignee:

National Semiconductor Corp. - Santa Clara CA

International Classification:

G06F 300

US Classification:

395275

Abstract:

An embedded modem that does not require a dedicated controller and operates with existing computer to interpret new and redefined communications interrupt requests. In response to an interrupt request, the control of the processor is transferred from the communications software to a driver program stored in the main memory for the processor. Under the operation of the driver program, the processor interprets control characters and causes the appropriate commands to be carried out in the modem. Once these commands have been processed, the control of the processor reverts back to the communications program. The processor thereby functions as a virtual controller that is interpreted to be an external controller by the communications program.