i.MX RT Crossover MCUsのトピックAN14808, can not find some functions in the document

AN14808, can not find some functions in the document

felix1 — Wed, 22 Apr 2026 03:48:15 GMT

In the AN14808, connect i.MX RT1170 to Quectel EC200A-CN USB 4G modem,

https://docs.nxp.com/bundle/AN14808/page/topics/details_for_implementation.html

can not find some functions in the document chapter 3.7, item g.

USB_HostCdcECM_ATInCallback(); USB_HostCdcECM_ATOutCallback(); dial_update_status(); dial_tx(); dial_rx(); lte_dial(); USB_HostCdcECM_EC200A_EP0_Callback(); update_ec200a_status(); ep0_communicate(); init_ec200a();

Where can find these sample code functions?

Re: AN14808, can not find some functions in the document

felix1 — Wed, 22 Apr 2026 06:06:03 GMT

I have found it in AN14808SW.zip, but in the document chapter 3.7, item b., it seems miss something in

case USB_HostCdcEcmRunDial:

Re: AN14808, can not find some functions in the document

EdwinHz — Fri, 24 Apr 2026 20:24:24 GMT

Hi @felix1,

In this case, you would need to add the missing part of:

case USB_HostCdcEcmRunDial

In order for it to match what you see on section d) of "7. In usb_ethernetif_freertos.c:"

Re: AN14808, can not find some functions in the document

felix1 — Mon, 27 Apr 2026 10:47:52 GMT

Hi @EdwinHz ,

I don't have RT1170 EVK and Quectel EC200A-CN, I use RT1020 EVK and EC200U-EU C4-P01 EVB

https://developer.quectel.com/doc/quecpython/Dev_board_guide/en/ec200x-evb.html

to test this application note.

For now, can not trigger the EC200U-EU EVB USB device attached, just show the log

USB host init success.

I check the host CONTROLLER_ID, and it seems correct for RT1020.

#if ((defined USB_HOST_CONFIG_EHCI) && (USB_HOST_CONFIG_EHCI)) #ifndef CONTROLLER_ID #define CONTROLLER_ID kUSB_ControllerEhci0 #endif #endif /* USB_HOST_CONFIG_EHCI */

Is there any USB difference I need to modify?

Re: AN14808, can not find some functions in the document

felix1 — Mon, 04 May 2026 03:09:20 GMT

Hi,

Anyone have tested the application note before? Can you give your hardware environment for reference, like RTXXXX EVK, Quectel modem module.

Re: AN14808, can not find some functions in the document

EdwinHz — Fri, 08 May 2026 22:03:33 GMT

Hi @felix1,

Considering that the AppNote was used for the RT1170 and that you are currently using an RT1020, I would highly suggest you check the USB example codes we provide on the RT1020 SDK as reference to ensure that the USB peripheral on the RT1020 is properly initialized according to its clock tree, power controls, and specific PHY requirements.