K66 Development Board USB HS Interface

[charles2]

I got confused on the advertised high speed usb port on the K66. I know there are two MCUs on the board, K20 and K66. And according to the schematic, one usb connecting to K20, which only provides full speed. Another one is connecting to the K66 full speed (USB1_DM, USB1_DP), and the actual high speed pins left at floating (USB0_DP,USB0_DM). 

There is no high speed usb connection on the schematic, but when I tested the examples, like device_composite_cdc_msc_sdcard, I can see the speed difference when changing settings of EHCI and KHCI on the firmware. Why does it behave like this? 

[Sabina_Bruce · Accepted solution]

Hello Charles,

Hope you are doing well.

The USB1_DP and USB1_DM have USB HS capability. 

You may refer to the reference manual for more information on the signal description.

I would also recommend to check Chapter 9 of the USB specification 2.0. Here you will find the different considerations to take when your device is capable of different speeds.

Hope it helps!

Sabina

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