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:
Jun. 25, 2002
Filed:
Apr. 06, 1999
Michael R. Steed, Round Rock, TX (US);
David W. Madden, Austin, TX (US);
National Instruments Corporation, Austin, TX (US);
Abstract
A USB-based data acquisition system including virtual DMA software which increases USB data transfer rates with minimal changes to DAQ driver level software. The virtual DMA software operates to receive or intercept DMA instructions provided by the DAQ driver level software to program a DMA controller to acquire data from the device. The virtual DMA software intercepts the DMA instructions and emulates operation of the DMA controller in software. The virtual DMA software operates to request the data in bulk packets from the device. The virtual DMA software then stores the received packets of data in the addresses specified in the DMA instructions. The virtual DMA software thus emulates operation of a DMA device, thus “fooling” the DAQ driver level software into thinking the data is being acquired using real DMA transfers. Thus, the present invention allows for much faster data transfers, while requiring minimal or no changes to the existing DAQ driver level software.