I am experiencing a problem with ENET_0 where the auto generated IP and protocol header checksums are both missing (zero), when the frame length is larger than 174 bytes. Checksum generation works perfectly with smaller frames, works intermittently with frames of between 174 and 190 bytes, and never works with frames larger than 190 bytes. I have verified the same behaviour with the S32 enet_rmii_udp example application.
I think this could be a timing issue, I'm starting to check clocking and caching. All Ethernet buffers and buffer descriptors are in uncached memory. Has anyone seen this problem before? Thanks.