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USB superspeed peripherals

Level 3
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Level 3


I am trying develop an UVC application with the FX3 board(CYUSB3KIT). I am using as a base the AN75779 document and the UVC_AN75779 example project. I needed to modify the project, based on the FX3 Technical reference guide. I had to add some simple GPIO and one complex GPIO for a clock signal. The documentation says i had to bitmasking the gpios(like in the cyfxgpiocomplexapp and the cyfxgpioapp example projects), but if i masked them the board not even enumerate. I could successfully setup the simple gpio pins if i did not masking them, but initialize them with override in the "CyFxUVCApplnInit" thread. But for the complex gpio pin i was not able to use this method. Can you help what can be the problem?

1 Solution
Moderator First question asked 1000 replies posted 750 replies posted

Hello Bence,

Based on my understanding from the latest project that was shared, you are making use of a 16 bit data bus. As mentioned in the pin description section of FX3 datasheet, GPIO 20 and 25 are used for the control signals and they cannot be directly configured over the IO matrix. You can override and use them. Please note that the API CyU3PDeviceConfigureIOMatrix () will fail if you configure one IO that is actually mapped to a peripheral as a GPIO. The control signals are mapped to the GPIF II block and it is not possible to directly configure them as GPIOs through the IO matrix configurations.

About the PWM issue, we used the same project that was shared in your previous response without any modification. We were able to see a PWM on GPIO 34. Please find the snapshot of the traces captured at our end using saleae logic analyzer:


I found that you have used a very small period for the PWM signal. Is this the actual requirement? If not then you can refer to the following KBA to understand how to calculate and set the period and duty cycle of the PWM signal:


Best Regards,

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