Question about merging usb_host_msd_fatfs to lwip tcpecho with FreeRTOS

[843395729]

Hi everybody:

I want to do one test about the fatfs,the function include LWIP/FATFS/UART/GPIO,the usb_host_msd_fatfs can work with freeRTOS,but failed when I merged it to the lwip_tcpecho_freertos example. the reason of failed was The USB enumeration failed when the FAT storage device connect to USB port.

I don't know how to fix it,could you give me some idea? 

the source code show at the attachment.

Test Environment：

SDK:SDK_2.5.0_EVK-MIMXRT1020，example: "usb host mad fatfs" & "lwip tcpecho freertos" .

Processors:IMX RT1020

IDE:MCUXpresso IDE v10.3.1_2233

Windows 7

HW：customer board(example 'usb_host_mad_fatfs' can work on it).

Thanks & Best regard!

[jingpan]

Hi Nick,

You put all data in SDRAM. I think not only USB, but also ENET will has problem. This is because these bus masters put their control and data exchange blocks in RAM, for example, USB Periodic Frame List. Since TCM do not need cache, anything written by USB/ENET MCU will get directly. But if you put these blocks in OCRAM, MCU will not know if the data is changed by other master. MCU will still read data from cache but not refresh it. So, if you hope to make full use of OCRAM, you should keep these control and data exchange blocks in DTCM.

Regards,

Jing