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:
Jan. 28, 1997
Filed:
Apr. 25, 1994
Mark W Welker, Spring, TX (US);
John S Thayer, Houston, TX (US);
Compaq Computer Corporation, Houston, TX (US);
Abstract
A computer system which includes a DMA controller on the local I/O unit which can be programmed by either the host processor or the local processor. Semaphore flags and lock bits are provided to allow determination of control of the local DMA controller and for passing information. Additionally, data alignment and padding circuitry is provided. The circuitry is informed of the logical data arrangement desired or utilized by the host processor or other devices and knows the data arrangement of the local processor. The circuitry properly obtains and realigns the data based on the transfer direction and data arrangement. The circuitry further properly zero pads the data when realignment is such that padding is necessary.