IMXRT1020EVK booting from SDRAM USB Host not working.

nicolasmuratore — Fri, 11 Dec 2020 22:19:28 GMT

Hi All, hope you are doing well, I was working with USB (host/device) examples of the SDK of the IMXRT1020EVK, I sucesfully mixed two usb apps host and device type.

I was trying to make a program that can handle both types and can boot from FlexSPI NOR FLash of the EVK, now this is working without problems.

The USB Host detect a pen drive and make a test, and when it starts like device a virtual com port is inicialized.

The idea is to use the same usb program and to generate an image to download in an SD card and then boot from SDRAM of the EVK using MCUBootUtility.

Right now I can sucesfully download an image to SD card and then boot from SDRAM, using DCD file and MCUBootUtillity, that is not a problem.

The problem is that after downloading the usb app into a SD card and booting from SDRAM only the usb device works fine, the usb host has enumeration problems.

The global variables are using the SRAM_DTC region (I read in another post that is important to not use the cacheable region of SRAM).

Why if I run from the external nor flash the usb host works fine, but if I run from SDRAM it not works? (In both cases usb device type works fine).

I will appreciate yours ideas.

Many thanks.

Re: IMXRT1020EVK booting from SDRAM USB Host not working.

danielchen — Sat, 12 Dec 2020 08:46:58 GMT

Please refer to below link

https://community.nxp.com/t5/i-MX-RT-Knowledge-Base/Using-NonCached-Memory-on-i-MXRT/ta-p/1183369

I hope it helps

Regards

Daniel

topic IMXRT1020EVK booting from SDRAM USB Host not working. in i.MX RT Crossover MCUs

IMXRT1020EVK booting from SDRAM USB Host not working.

Re: IMXRT1020EVK booting from SDRAM USB Host not working.