USB 2.0 K70

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USB 2.0 K70

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Microfelix
Contributor IV

hello

I'm using various micro-series Kinetis K70, K22 and MQX 4.0.2.

I'm using the USB, but I can not work with USB 2.0.

Communication is very slow.

Is there any change to the driver that allows you to work with the 2.0?

Maurizio

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soledad
NXP Employee
NXP Employee

Hi Maurizio,

The only option to change the speed in a  usb device it is not by software it is by hardware, you need to add a pull-up resistor from D+ or D- depending of the speed, you want to select.  For a full speed device, the pull-up is attached to the D+ signal.  When the host detects this voltage change then it begins the enumeration process at the full speed rate.  If the voltage change is detected on the D- line, then the enumeration happens at low speed.

usbimage.png


Have a great day,
Sol

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Microfelix
Contributor IV

dear SOL

I tried to put down pullup on D + and D-host.

With a pen-drive usb 2.0, I always loading very slow.

Should I do anything else?

Maurizio

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