topic Re: AN14808, can not find some functions in the document in i.MX RT Crossover MCUs

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.