How to make the speed of USBD on nRF5340 reach to 12Mbps

[Tom.Fu]

Dear Support Team

As said in the nRF5340 product specification file, the nRF5340's USBD support full-speed 12Mbps.

I would like to use the USBD on nRF5340 to store data to the NAND Flash, which example is recommended and how to make the USBD speed reach to the 12Mbps in this case?

[Sigurd]

Hi,

1) 12 mbps is the raw bus speed, and the USB protocol, itself, reduces these numbers.

2) Also, if you plan to use the QSPI peripheral, then that do not support NAND flash instructions. It supports NOR flash instructions.

[Tom.Fu]

Hi Sigurd

Ok, in the USB part, what is the average USB speed of nRF5340 in the normal conditions? Many thanks.

[Sigurd]

Depends on the USB class, but for e.g. USB CDC ACM, see the numbers in this post:  RE: How to transfer data through EPOUT2 in usbd-custom-hid-ep example 

[Tom.Fu]

Hi Sigurd

For the  MSC and the CDC ACM, Could the red circles speeds represent the fastest speed the nRF5340 USB could achive?

And is there USB mass storage sample in the nRF connect sdk for nRF5340? Many thanks.

[Sigurd]

Tom.Fu said:

For the  MSC and the CDC ACM, Could the red circles speeds represent the fastest speed the nRF5340 USB could achive?

I think those are good estimates, ballpark numbers for the nRF5340 as well.  

Tom.Fu said:

And is there USB mass storage sample in the nRF connect sdk for nRF5340? Many thanks.

Yes, there is a sample here: https://github.com/nrfconnect/sdk-zephyr/tree/main/samples/subsys/usb/mass