Need help adding ethernet to 5748G

[MattJCole]

I need help adding Ethernet to the DEVKIT-MPC5748G. I configured all of the pins to exactly how the  lwip_mpc5748g demo but I can not make the clock configuration match. the demo has ENET0_CLK set to ENET_RMII with a frequency of 50 MHz. The one I created has the clock source set to F40 with a frequency of 40 MHz. What am I doing wrong? Is there any documentation on how to configure the ethernet?

[MattJCole]

Thanks for the clarification. The difference between what you had and what the demo was setup scared me. I was afraid I would configure the ethernet in a way it would not work on occasionally and you know that kind of bug is a nightmare to debug. Also I hope you are felling better.  

[MattJCole]

The demo for 3.0.3 doesn't match what you have in your setup. see attached picture. Is ENET0_CLK or ENET0_TIME_CLK supposed to have the clock source set to ENT_RMII

[lukaszadrapa]

I'm sorry for delayed response, I was out of office due to some health issues.

I will ask SDK team if they can fix this.

In fact, the only configurable clock is ENETx_TIMER:

If you have other clocks like F40 or F80 set to its maximum, there will be no problem.

The timer clock is then an auxiliary clock signal for the ENET module that is not needed for normal operation. It is used for IEEE 1588 Time-Sensitive Networking (TSN) applications, which our ENET module supports in hardware. This clock is specifically used for time-stamping IEEE 1588 datagrams.

Regards,

Lukas

[MattJCole]

Ignore the error. I figured out why I was getting it. The demo for the LWIP SDK 3.0.3 doesn't have enough RAM assigned in the linker file to it based on the configuration. I reduce the amount of RAM assigned to the FreeRTOS and it was able to compile. 

[MattJCole]

That is not what I get for 3.0.3. Also I needed reinstall my IDE because it was acting funny and now the LWIP demo will only compile under Flash build setting not RAM. If I build it under RAM is get the following compile error.

Description Resource Path Location Type
Ld error: lwip_mpc5748g.elf section `.bss' will not fit in region `SRAM' lwip_mpc5748g C/C++ Problem
Ld error: region `SRAM' overflowed by 141456 bytes lwip_mpc5748g C/C++ Problem
Ld error: region `SRAM' overflowed by 36912 bytes lwip_mpc5748g C/C++ Problem
make: *** [makefile:71: lwip_mpc5748g.elf] Error 1 lwip_mpc5748g C/C++ Problem

[MattJCole]

That is enabled and the frequency is set to the correct value. I tried my best to make it match the LWIP demo but there are settings I can't  make match. I also get a warning when I set the PH1 Divider to /4 even though the demo has it configured that way. I attached my code. I hope you can figure out why I can not make my project match the demo.

[lukaszadrapa]

It looks like you used demo from SDK 3.0.0 for comparison, right? This one seems to be wrong, PHI1 needs to be 80MHz, so divider /8 must be used:

 I can see that this is fixed in 3.0.3. so the warning is correct. The same about ENET_CLK:

So, go on with your current configuration.

Regards,

Lukas

[lukaszadrapa · Accepted solution]

Hi Matt,

have you enabled the external clock like this?

Regards,

Lukas