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. 31, 1995
Filed:
Dec. 30, 1991
Martin Sodos, San Jose, CA (US);
Sun Microsystems, Inc., Mountain View, CA (US);
Abstract
A method and apparatus for supporting multiple DMA channels by splitting data transfers for each channel into sequences of data slices and interleaving on a slice-by-slice basis. While the control of transfer resources may be shifted among the DMA channels, the ordering of the data slices for each channel is preserved. The present invention also discloses a circuit architecture capable of supporting the multiple interleaving DMA channels. The circuit architecture comprises a dual-port memory, channel sequencer, and channel interleave control. The dual-port memory stores slices of data to be transferred through the channels. A channel sequencer maintains the channel ordering of data slices in the dual-port memory. A channel interleave control unit allows channels to interleave their data transfers by monitoring the channel interleave size, current data transfer count and total transfer count per channel. A second channel is allowed to transfer data through the same medium as a first channel either when the first channel has reached its channel interleave size, or when the first channel has transferred its requested total transfer count, thus providing efficient bus utilization.