Cypress Perform

Home > Design Support > Cypress Developer CommunityTM > Cypress Forums > USB Controllers > PKTEND usage: Problem about short packet

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



PKTEND usage: Problem about short packet
Moderator:
RSKV

Post Reply
Follow this topic



PKTEND usage: Problem about short packet

byeyear posted on 08 Feb 2012 5:57 PM PST
Top Contributor
29 Forum Posts

Hello,

    I have a problem about PKTEND# usage with short packet.

    I set DMA buffer size as 1024bytes on device side, and set "bytes to transfer" as 2048 on Cypress Control Center. When I wants to send a short packet, for example, 1020 bytes, I assert pktend# with last word, and this is ok.

    But when I wants to send 1024 bytes and assert pktend# with last word, I can not read data from Control Center. Should I append a ZLP on this situation? Why does not FX3 consider the pktend# valid ?




Re: PKTEND usage: Problem about short packet

aasi posted on 08 Feb 2012 07:03 PM PST
Cypress Employee
1073 Forum Posts

You're sending the packet of the exact maximum packet size if you want to terminate the transfer with that then you should be sending a ZLP.

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.