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USB superspeed peripherals Forum Discussions

NoAr_1540581
Level 5
Level 5
250 sign-ins 100 replies posted 100 sign-ins

Hello

 

I think Streamer.exe can transfer data up to 4MB in length.
The above formula is recognized as follows.
- Packet size * Max EP packet size = 256 x 16KB = 4MB.
 
Q) However, there is a question about the MAX EP packet size mentioned above.
Normally, the MAX packet size of EP is recognized as "1kB", but why Streamer is recognized  "16KB (= 16384)"  as MAX EP packet size? Could you please tell me  the reason  on this ? 
 
Best Regards
Arai
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AliAsgar
Moderator
Moderator
Moderator
250 solutions authored 750 replies posted 50 likes received

Hi Arai-San,

The Streamer recognizes 16KB as MAX EP packet size because Endpoint burst might be set to 16 in descriptors.
If burst is set to 16, max packet size will be 1KB*16 = 16KB.

In the descriptor files, burst length is configured in the super speed endpoint companion descriptors of the EP being used. In the firmware source file, burst length is also set during the endpoint configuration.

Best Regards,

AliAsgar

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1 Reply
AliAsgar
Moderator
Moderator
Moderator
250 solutions authored 750 replies posted 50 likes received

Hi Arai-San,

The Streamer recognizes 16KB as MAX EP packet size because Endpoint burst might be set to 16 in descriptors.
If burst is set to 16, max packet size will be 1KB*16 = 16KB.

In the descriptor files, burst length is configured in the super speed endpoint companion descriptors of the EP being used. In the firmware source file, burst length is also set during the endpoint configuration.

Best Regards,

AliAsgar

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