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Adaptive Stream Configuration Method on AT Attachment Interface Hard Disk Drive Disclosure Number: IPCOM000013298D
Original Publication Date: 2000-Feb-01
Included in the Prior Art Database: 2003-Jun-18

Publishing Venue



Disclosed is a method to handle multiple streams of Audio and Visual data efficiently using a single hard disk drive of AT Attachment Interface. The AT Attachment Interface defined in ATA standard is designed to handle data for computers. In other hands, a certain amount of Audio and Visual (AV) Stream data has to be handled in a certain period for AV applications. The data for AV applications are usually a series of data in time per source so that it is called Stream. The way a host can access AV Stream data in a device easily stream by stream is needed for the interface to be used with AV applications. The number of AV Streams a host should handle at a moment will not be able to be pre-defined to the fixed number. The capacity of each AV Stream will be changed depending on what the source of the AV Stream is and the source may be changed in time frame. Based on these AV Stream characteristics, under the multiple stream configuration on a single hard disk drive of AT Attachment Interface, Adaptive Stream Configuration Method provides the way how to share a limited capacity of a single hard disk drive efficiently for multiple streams. Adaptive Stream Configuration Method assumes the multiple stream configuration on a single hard disk drive. With the Adaptive Stream Configuration, a host shall make streams active by setting their capacity. The host doesn't have to make active all of streams at once, which have been set up. The host may set the capacity of an AV Stream when the host gets to use the AV Stream. Moreover, the host can make the AV Stream inactive which has been made active at the last. The host shall make active the AV Streams with smaller stream numbers among the inactive streams at the moment. After the inactivation of a stream, the stream can be made active again with the different capacity. This provides the flexibility for the AV Stream configuration. For instance, a host sets up 2 streams, stream #1 and #2, for a device. The host may make stream #1 active with the capacity 2000 sectors but may keep stream #2 inactive. After a while, the host gets to use one more stream and make stream #2 active with the capacity 4000 sectors. Even when the data of stream #1 becomes useless, the host cannot make stream #1 inactive without the inactivation of stream #2., After stream #2 is made inactive, the host can make stream #2 active again with the capacity 3000 sectors The following indicates an example of command definition to activate or inactivate AV Streams which are for Adaptive Stream Configuration Method. By setting or clearing AS (Activate Stream) bit of Sector Count register, the host can activate or inactivate the AV Stream specified in bit-2 to bit-0 of Features register using this Set Max AV Stream Address command. Set Max AV Stream Address