problem about ZLP | Cypress Semiconductor

problem about ZLP

Summary: 1 Reply, Latest post by RSKV on 01 Feb 2014 06:26 PM PST
Verified Answers: 0
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shmilyjldx's picture
18 posts


       The data is transferred from 3014 to pc. The configuration of 3014 is below:

1. DMAChannel with 1 producers(CY_U3P_CPU_SOCKET_PROD) and 1 consumer (CY_U3P_UIB_SOCKET_CONS_3);

2.  16KB buffer size in a DMA channel;

3.   burst size is 16

FX3 transfers 16K data followed by 4B data continually using “CyU3PDmaChannelCommitBuffer”.

Two blocks(16K each block) allocated from USB host side to receive data from FX3.

I test it in Intel and Renesas controller, the result is pefect.but in Asmedia host I get 16K data, 4 data and a zlp,it is so wired, why receive a zlp ? how to solve it?


rskv's picture
Cypress Employee
1134 posts


Did you get a chance to look at the USB traffic on the bus. Did you find any difference when you use FX3 with the Asmedia host controller. Please share the USB trace here so that I can also take a look at it to understand what exactly is going on.


Sai Krishna.

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