LWIP example is not working in BOARD_SDRAM(external RAM).

[JainamShah]

Hello,

I am working on the lwip_dhcp_freeRtos example. I have changed the default memory settings in example code to run the lwip stack in the external RAM. After doing this device can not be able to go into the bound state. I am attaching the configurations below.

Actually, I am using the LCD in my project which overflows the SDRAM_DTC segment. So, I have changed the memory settings as below. 

After changing this the DHCP state got stuck at the SELECTING state.  

Please help me to solve this issue. 

Thank you.

[jingpan · Accepted solution]

Hi @JainamShah ,

You can refer to these post. ENET descriptors and data buffers must be put into noncacheable space. DTCM/ITCM is noncacheable. If you put them in OCRAM/SDRAM, you must set this space as noncacheable.

https://community.nxp.com/t5/MCUXpresso-IDE/Running-and-debugging-program-in-SDRAM/m-p/1405167

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

https://community.nxp.com/t5/i-MX-RT/USB-Host-enumeration-fails/m-p/1436138

https://community.nxp.com/t5/i-MX-RT/Ideal-memory-configuration-for-best-Ethernet-performance/m-p/15...

Regards,

Jing