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Hi
I was able to add the CDC to the CX3 UVC project correctly, but I still don't understand the variation of the 0x39, 0x01,//0xe5,0x00, /* Length of this descriptor and all sub descriptors */ parameter in the descriptor,hope someone can help me to answer it,Thank you
Now that the parameters in my descriptor have changed I don't know how I should change them
Regards,
Yaqi
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USB Superspeed Peripherals
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Hello,
In the configuration descriptor, the /* Length of this descriptor and all sub descriptors */ field is expected to hold the length of all the descriptors which includes UVC interface related descriptors and CDC interface related descriptors.
As per the reference snippet, the /* Length of this descriptor and all sub descriptors */ is changed from 0xe5 (length of UVC descriptors) to 0x0139 (total length of UVC + CDC descriptors) which means 0x54 is the length CDC interface.
So, for the new configuration /* Length of this descriptor and all sub descriptors */ will be 0xda + 0x54 = 0x012E
Also, the number interfaces (/* Number of interfaces */) will change from 2 to 4 as 2 more CDC interfaces will be added.
You can refer to this KBA https://community.cypress.com/t5/Knowledge-Base-Articles/Adding-Communication-Device-Class-Interface...
Rashi
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Hello,
In the configuration descriptor, the /* Length of this descriptor and all sub descriptors */ field is expected to hold the length of all the descriptors which includes UVC interface related descriptors and CDC interface related descriptors.
As per the reference snippet, the /* Length of this descriptor and all sub descriptors */ is changed from 0xe5 (length of UVC descriptors) to 0x0139 (total length of UVC + CDC descriptors) which means 0x54 is the length CDC interface.
So, for the new configuration /* Length of this descriptor and all sub descriptors */ will be 0xda + 0x54 = 0x012E
Also, the number interfaces (/* Number of interfaces */) will change from 2 to 4 as 2 more CDC interfaces will be added.
You can refer to this KBA https://community.cypress.com/t5/Knowledge-Base-Articles/Adding-Communication-Device-Class-Interface...
Rashi