US 6,720,968 B1Granted

Video acquisition system including a virtual dual ported memory with adaptive bandwidth allocation

AssigneeNational Instruments Corporation

InventorsCary Paul Butler, B. Keith Odom, Kevin L. Schultz, Charles G. Schroeder

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Abstract

A video capture system and method whereby video frames or images, which are received in one of a plurality of possible formats, are acquired and stored into on-board memory in an image format. The image data can then be transferred into system memory at an optimum rate. The video capture system comprises a host computer, including a video capture board, which is coupled to a video source, such as a video camera. The video source provides digital video data in a first format of a plurality of different possible formats. The video capture board includes a memory controller which receives the digital video data in the first format and selectively provides the digital video data to the buffer memory in an image format. The memory controller includes address generation logic for generating buffer memory addresses for storing the video data to the buffer memory in the image format. The address generation logic is programmable with configuration information corresponding to the first format and uses the configuration information to generate the addresses.

Claims22

Dependent claims

An image acquisition device for acquiring one or more video images from a video source, the image acquisition device comprising:

an input for receiving digital video data from a video source;
a buffer memory coupled to said input which stores said digital video data;
and
a memory controller coupled to the input and to the buffer memory, wherein the memory controller comprises:
write control logic which receives said digital video data from said video source and writes said digital video data to the buffer memory;
read control logic which is operable to read said digital video data from the buffer memory;
and
arbitration logic coupled to the write control logic and the read control logic which receives requests from each of the write control logic and the read control logic and grants buffer memory access to one of the write control logic or the read control logic;
wherein the arbitration logic is operable to monitor said requests from each of the write control logic and the read control logic and dynamically allocate bandwidth to the write control logic and the read control logic based on said requests;
wherein, if both a write request and a read request are pending, the arbitration logic is operable to determine if the write request can be safely delayed;
wherein the arbitration logic grants buffer memory access to the read control logic if both a write request and a read request are pending and the write request can be safely delayed;
wherein the arbitration logic grants buffer memory access to the write control logic if both a write request and a read request are pending and the write request cannot be safely delayed.

9 more elements

A method for acquiring one or more video images from a video source, the method comprising:

receiving digital video data from a video source;
generating one or more write requests to write said digital video data in a buffer memory;
generating one or more read requests to read digital video data from said buffer memory for transfer to a computer memory;
receiving at least one of said write request and said read request;
arbitrating among said at least one of said write request and said read request;
granting buffer memory access to one of said write request or said read request in response to said arbitrating;
performing a write operation to write said digital video data to the buffer memory in response to granting buffer memory access to said write request;
performing a read operation to read digital video data from the buffer memory in response to granting buffer memory access to said read request;
wherein said arbitrating monitors said write requests and said read requests and operates to dynamically allocate bandwidth to said write operations and said read operations based on said requests;
wherein, if both a write request and a read request are pending, said arbitrating determines if the write request can be safely delayed;
wherein said arbitrating selects said read request for granting of buffer memory access if both a write request and a read request are pending and the write request can be safely delayed;
wherein said arbitrating selects said write request for granting of buffer memory access if both a write request and a read request are pending and the write request cannot be safely delayed.

9 more elements

Dependencies are inferred from the claim text.