Forum Discussion
Hi Konrad,
You are right. Looks like TSE small MAC doesn't support 8 bits option.
- The only way to enable 8 bits FIFO option is to use other TSE MAC configuration like 10M/100M/1000M MAC option
The recommended and right way is to use the the mask bit signal "ff_tx_mod[1:0]" for 32 bits transfer as I explained in my first reply. You will need to modify your Tx source user logic design accordingly to use mask bit signal.
Thanks.
Regards,
dlim
- Konrad5 years ago
New Contributor
I have found the problem I had. I had connected 125MHz from the PLL instead of 25MHz from the PHY. A stupid oversight I had meant to correct.
For other users with problems, the avalon-st as in the trace I have posted seems to be correct.
I have another problem now. I lose the first 2 bytes that I send, i.e. the upper MSB bytes of the first 32-bit word clocked into the TSE. I can send multiple 32-bit words consistently without error, but the first two bytes are never sent. It is as if the TSE is dropping these bytes, as the other half of the 32-bit word is OK.
e.g. I send 0x11223344 0x55667788 0x99AABBCC etc, and I receive 0x33445566 0x778899AA 0xBBCCDDEE
I am sending the data directly into a piece of test equipment that guarantees that the pre-amble is OK.
Even more confusing is that if I set the TSE to fill in the MAC address, the received MAC is in the correct place, i.e. 0x33445566 0x7788mmmm 0xmmmmmmmm
The SignalTap shows that the 32-bit words on the avalon-st are OK and not corrupted,
If anyone has any ideas as to what I am doing wrong I would love some feedback,
Konrad
- Konrad5 years ago
New Contributor
found it, ...if you tick the Megafunction "Align to 32-bit boundaries" it clearly states in the user guide that the core drops 2 bytes...missed it