RTOS/TMS320C6657: NIMU: Short ethernet packet bad CRC sending

Peter Demenuk

Prodigy 160 points

Part Number: TMS320C6657

Tool/software: TI-RTOS

I have found short UDP packets (less 60 bytes of thernet frame) have bad CRC. I also have found incorrect code place:

pdk_c665x_2_0_5\packages\ti\transport\ndk\nimu\src\v0\nimu_eth.c

line: 339

if( PBM_getValidLen(hPkt) < 60 )
PBM_setValidLen (hPkt, 64 );

Removing these strings leads to correct short packet sending..

over 8 years ago

0 Yordan Kovachev over 8 years ago

TI__Guru**** 161600 points

Hi,

I've notified the sw team. Their feedback will be posted here.

Best Regards,
Yordan

0 lding over 8 years ago in reply to Yordan Kovachev

TI__Guru* 95265 points

Hi,

The minimum Ethernet frame size is 64 bytes by IEEE802.3. So we set the packet length to 64 in the NIMU driver when sending short packets out by EMAC . It looks that the checksum is not re-calculated so there are the error. Let me open a ticket and check with our dev team.

Regards, Eric

0 Peter Demenuk over 8 years ago in reply to lding

Prodigy 160 points

Eric,

I am of the same opinion. Only I want to pay attention NIMU does incorrect padding and EMAC does it independently correctly.

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RTOS/TMS320C6657: NIMU: Short ethernet packet bad CRC sending