The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 29, 2000
Filed:
Jan. 31, 1997
Arnold R Colterjohn, Spring, TX (US);
Peter J Brown, Houston, TX (US);
Douglas E Stewart, Houston, TX (US);
Compaq Computer Corporation, Houston, TX (US);
Abstract
A computer system implements a standard modem without the use of a microcontroller. Instead, a digital signal processor is provided on an expansion card, but with direct links to the computer system itself. The code usually implemented in the microcontroller is instead implemented as a virtual modem controller to be called by the operating system of the computer itself. Further, this virtual modem controller includes a virtualized UART, that appears to the operating system software as a hardware UART, and the operating system driver software need not even have its input and output instructions replaced. Instead, debug registers are provided as breakpoints whenever an input/output instruction is executed to the I/O port range at which the UART would normally appear.