Content Terminated DMA
AssigneeQUALCOMM Incorporated
InventorsKevin Allen Sapp, James Norris Dieffenderfer
Life of this patent
Estimating the term…
Abstract
A Content-Terminated Direct Memory Access (CT-DMA) circuit autonomously transfers data of an unknown length from a source to a destination, terminating the transfer based on the content of the data. Filter criteria are provided to the CT-DMA prior to the data transfer. The filter criteria include pattern data that are compared to transfer data, and transfer termination rules for interpreting the comparison results. Data are written to the destination until the filter criteria are met. Representative filter criteria may include that one or more units of transfer data match pattern data; that one or more units of transfer data fail to match pattern data; or that one or more units of transfer data match pattern data a predetermined number of times.
Claims27
A Content-Terminated Direct Memory Access (CT-DMA) circuit, comprising:
- at least one data transfer interface;
- memory operative to store filter criteria;
- a comparator operative to compare transfer data to one or more filter criteria;
- and
- a controller operative to terminate a DMA transfer in response to the comparator output.
A method of transferring an unknown amount of data from a source to a destination, comprising:
- successively reading transfer data from the source;
- comparing transfer data to predetermined pattern data;
- determining when to terminate a transfer in response to the comparison;
- and
- successively writing transfer data to the destination until terminating the transfer;
- wherein these method steps are performed autonomously of a processor.
A computing system, comprising:
- a data source operative to provide data;
- a data destination operative to receive data;
- a Content-Terminated Direct Memory Access (CT-DMA) circuit operative to perform a transfer data from the source to the destination, and further operative to terminate the data transfer in response to one or more values of the transfer data;
- and
- a processor operative to initialize the CT-DMA circuit;
Dependencies are inferred from the claim text.