Cypress Perform

Home > Design Support > Cypress Developer CommunityTM > Cypress Forums > USB Controllers > two questions of bmattribute

Bookmark and Share
Cypress Developer CommunityTM
Forums | Videos | Blogs | Training | Rewards Program | Community Components



two questions of bmattribute
Moderator:
RSKV

Post Reply
Follow this topic



two questions of bmattribute

才哥 posted on 08 Jul 2011 6:32 AM PST
Top Contributor
40 Forum Posts

 

 

Hi! Anand!

 

1,In the endpoint descriptor,when in isochronous transfer the bmAttributes's bit 3:2 defines Synchronization Type as :No Synchronization/Asynchronous/Adaptive/Synchronous, what's the differences among them?  To maximrize the transfer speed, how to set it?

 

2,The bmAttributes's bit 5:4 defines Usage Type as :Data endpoint/Feedback endpoint/Implicit feedback Data endpoint, what's the differences among them?  

 

Thank you!




Re: two questions of bmattribute

aasi posted on 08 Jul 2011 08:25 AM PST
Cypress Employee
1090 Forum Posts

Looking at your question I assume you're talking about a specific USB class protocol and not generic USB protocol. Is my understanding right? If so please let me know the protocol  you're referring to, if you can provide me a link to the document you're referring it would be much better.

Regards,

Anand



Re: two questions of bmattribute

才哥 posted on 08 Jul 2011 09:18 AM PST
Top Contributor
40 Forum Posts
oh,I just be curious about it when I read the standard endpoint descriptor in USB specification's chapter 9.6.6. I don't know how to set the value. but I have transfered succesfully when set them to zero.Thank you! Anand.Best Regards.

Re: two questions of bmattribute

aasi posted on 08 Jul 2011 09:23 AM PST
Cypress Employee
1090 Forum Posts

I've not really paid attention to this part of the spec. Section 5.12.4 (page 72) seems to explain this in detail.

Regards,

Anand






ALL CONTENT AND MATERIALS ON THIS SITE ARE PROVIDED "AS IS". CYPRESS SEMICONDUCTOR AND ITS RESPECTIVE SUPPLIERS MAKE NO REPRESENTATIONS ABOUT THE SUITABILITY OF THESE MATERIALS FOR ANY PURPOSE AND DISCLAIM ALL WARRANTIES AND CONDITIONS WITH REGARD TO THESE MATERIALS, INCLUDING BUT NOT LIMITED TO, ALL IMPLIED WARRANTIES AND CONDITIONS OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT OF ANY THIRD PARTY INTELLECTUAL PROPERTY RIGHT. NO LICENSE, EITHER EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, IS GRANTED BY CYPRESS SEMICONDUCTOR. USE OF THE INFORMATION ON THIS SITE MAY REQUIRE A LICENSE FROM A THIRD PARTY, OR A LICENSE FROM CYPRESS SEMICONDUCTOR.

Content on this site may contain or be subject to specific guidelines or limitations on use. All postings and use of the content on this site are subject to the Terms and Conditions of the site; third parties using this content agree to abide by any limitations or guidelines and to comply with the Terms and Conditions of this site. Cypress Semiconductor and its suppliers reserve the right to make corrections, deletions, modifications, enhancements, improvements and other changes to the content and materials, its products, programs and services at any time or to move or discontinue any content, products, programs, or services without notice.

Spec No: None; Sunset Owner: KXP; Secondary Owner: VWA; Sunset Date: 01/01/20