Hello,
I developed a wee Gigabit MAC but with quite a different setup, Virtex 2 Pro (with my MAC + Internal MGT - 16 bit wide @ 62.5MHz) + Copper SFPs (with embedded Marvell 88E1111 in SGMII mode) PC
I did use Ethereal, and noticed that crc errored packets were filtered out, not sure if it was the SFP, the PHY in the PC or the PC driver, I'm positive that packets were not getting to Ethereal at all. I also noticed that packets smaller than 64 bytes were also filtered out and I am pretty sure it was the Driver in my PC.
For testing I used a ping frame...
--=============================================--
--IP DA (192.168.0.85 : c0.a8.00.55)
--IP SA (192.168.0.33 : c0.a8.00.21)
--Header Length & IPv4 = x"4500"
--IP Datagram = x"0800"
--SA = 12.34.56.78.9a.bc (it doesn't really matter)
--DA = 00.0d.88.b5.88.71 (change it to yours, it doesn't really matter in promiscous mode)
--=============================================--
constant C_GBE_DATA : word32_array(18 downto 0) := ( X"68697071", X"64656667", X"77616263", X"73747576", X"6f707172", X"6b6c6d6e", X"6768696a", X"63646566", X"04006162", X"485c0100", X"00550800", X"0021c0a8", X"96b3c0a8", X"00002001", X"003c8247", X"08004500", X"56789abc", X"88711234", X"000d88b5" );
Bytes go out like: 00 - 0d - d8 - b5 - 88 - 71 ...
FCS for the packet above => X"257eaf61"
On thing I recommend is using loopback if your PHY supports it, and also the internal CRC if the PHY provides one (just for testing) before trying to send packets to your PC.
Regards,
--
Ignacio Ulises Hernandez
" I'm not normally a praying man, but if you're up there, please save me,
Superman!" - Homer Simpson ;O)
"ashwin" wrote in message
news:1130865877.899697.324060@g44g2000cwa.googlegroups.com...
> Hello everyone,
>
> I am sending an ethernet packet(64 bytes) from the fpga to the PC
> in order to test the ETHERNET PHY chip onboard.
> The interface from the fpga to the ethernet PHY for the data is 4
> bits.
>
> My PC mac address is 00-01-80-3F-6C-E6
>
> a)So should i send the LSBs first like
> in this order, 6,E,C,6,F,3,0,8,1,0,0,0 or the MSBs first
>
>
> b) I have installed ethereal software on my PC and i am unable to
> detect the ethernet packet in it.
> 1) I am pretty sure my CRC is wrong for whatever data i have, so
> can ethereal still detect even when crc is wrong?
>
> 2)i used the scope , and i am able to see some data going from
> fpga to the ethernet PHY. But the nothing gets detected in the PC. What
> could be the reason?
>
> One of the member in this group recommended not to see the data
> coming out of the ETHERNET phy , since its at 125 mhz and its not
> being detect correctly using a scope.
>
>
> 3)Can anyone compute the crc check for whole ethernet packet for which
> my destination addres is as above? Data doesnt matter,it can be any
> value.?Source address also doesnt matter, since it is fpga mac address.
>
> 4) Can anyone guide me on hardware implementation of crc using
> vhdl
>