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USB hosts hubs transceivers Forum Discussions

Mike22
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Why do I need two LEDs for green? How does pin strapping for green LED work?

dphan1_0-1659385368943.png

 

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Ajeethkumar
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Hi David Phan,

Thanks for posting in Infineon Developer Community!

Pin 3 of CYUSB3314(HX3) is used for two functionalities, PORT_DISABLE[0](Pin strapping) and DS1_GREEN.

Pin-strapping is used for custom configuration and the functionality is made by measuring the state of the particular GPIO(GPIO as Input) when HX3 boots. Once boots, this pin has no other functionality and hence the same pin is re-used for the LED indication(GPIO as Output) after boot.

For Pin-strapping either the GPIO is made to detect High or Low. With our HX3 DVK, one can choose either of these using a 3-pin jumper. So, two sets of LEDs are needed for LED indication functionality based on the Polarity of the LED. But in your custom board, you don't need two LEDs but only one based on the Pin-strapping polarity.

Thanks,
Ajeeth

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Ajeethkumar
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Moderator

Hi David Phan,

Thanks for posting in Infineon Developer Community!

Pin 3 of CYUSB3314(HX3) is used for two functionalities, PORT_DISABLE[0](Pin strapping) and DS1_GREEN.

Pin-strapping is used for custom configuration and the functionality is made by measuring the state of the particular GPIO(GPIO as Input) when HX3 boots. Once boots, this pin has no other functionality and hence the same pin is re-used for the LED indication(GPIO as Output) after boot.

For Pin-strapping either the GPIO is made to detect High or Low. With our HX3 DVK, one can choose either of these using a 3-pin jumper. So, two sets of LEDs are needed for LED indication functionality based on the Polarity of the LED. But in your custom board, you don't need two LEDs but only one based on the Pin-strapping polarity.

Thanks,
Ajeeth

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Mike22
Level 1
5 sign-ins First reply posted First question asked
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Hi Ajeeth,

Thanks for your explanation. I select three LEDs for DS1 port status as follow. When HX3 boots the pins will be measured low per the pull downed resistors. After booting the same  pins are used for LED indication(active high to turn on LED). Is this correct?

dphan1_0-1659467161058.png

 

 

 

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Ajeethkumar
Moderator
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Moderator

Hi,

Yes, Your understanding is correct.

Thanks,
Ajeeth

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