topic Re: USB0 host mode downstream ports in LPC Microcontrollers

USB0 host mode downstream ports

manuela_mendez — Mon, 03 Mar 2025 13:27:59 GMT

Hello NXP Experts,

on p57, Rev. 2.3 of LPC55S2X_LPC552X datasheet it states the following:

Section 7.23.1.2 USB0 host controller: Features: "Two downstream ports"

Could you please detail what this means? can two devices be connected to same PHY? where can i find more info either as a code or appnote?

Thanks in advance!

Re: USB0 host mode downstream ports

diego_charles — Thu, 06 Mar 2025 18:07:54 GMT

Hi @manuela_mendez

Thank you for your reply,

Bascially, the number of downstream ports indicated by the datasheet is the number of physical downstream ports supported by the USB0 in host controller mode.

Below some screenshots of descriptions and diagrams that I found by checking the USB 2.0 specification, please take a look at its terminology.

Personally, I found this figure more explanatory.

Taking the information from above, I like to see it this more practical way: according to the spec and the DS specification , we should be able to connect to the host controller a HUB with two devices attached to it. Each device would be a downstream port, which upstreams data.

I hope this helps, if you are facing any particular issues with your application and our LPC55xx MCU feel free create another thread and we will be happy to check.

Diego

Re: USB0 host mode downstream ports

manuela_mendez — Mon, 10 Mar 2025 10:53:23 GMT

Hello @diego_charles : Thanks a lot for clarification!