anyone used legacy descriptors in MPC5748G enet

[dheerajr1]

Hi, 

I'm able to transmit the frame by programming the MPC5748G ENET Controller register using Legacy Descriptors, It is transmitting the frame which is visible at wire shark, but it also generates the EIR.EBERR and EIR.BABT interrupt.

EIR.BABT interrupt this is generated when frame is transmitted which exceeded maximum length but in this case frame length is only 44 bytes and EIR.EBERR this is bus error but buffer address is correct and descriptor address is correct.

please help with this it is very helpful if anyone can provide demo code using legacy descriptors.

And It is transmitting the frame only when buffer length is exceeded the threshold length. I'm attaching the register dump and code.

[PetrS]

Hi,

not sure if there is any MPC5748G example using legacy descriptors.

You can refer to AN4577 (https://www.nxp.com/docs/en/application-note/AN4577.pdf ) and its SW package. It is for MPC564xC but the module is very similar.

Also you can look at below thread, where you can find some useful information about ENET configuration. There are some examples too, but enhanced descriptors are used, I think.

MPC5748G ENET 

Finally, check if RX/TX descriptors and buffers are properly aligned (128-bit aligned, i.e. evenly divisible by 16) and whole placed in non-cacheable memory region.

BR, Petr