CRC32 for ethernet

Question

I have implemented a parallel CRC32 circuit with VHDL. My circuit produces identical results when compared to the page http://ghsi.de/CRC/index.php?Polynom=100000100110000010001110110110111&Message=123456789 used poly is the standard 100000100110000010001110110110111 and the message is the standard test 123456789 in hex

however, the results produced by the standard components in Altera devices are identical to this page "http://www.zorc.breitbandkatze.de/crc.html" even when I turn off reverse data bytes and reverse crc bytes, and set initial value and final exor to "00000000" I still get totally different results from the first online tool (and my circuit)

Is it possible to explain the difference in the way those two tools work?

Answer 1

The ghsi site expects the message as hex digits, whereas the breitbandkatze site is expecting characters (though you can use %xx for hex digits there).

So, if on the ghsi site you enter "313233343536373839", you will get the same result as entering "123456789" on the breitbandkatze site, assuming that you also set the initial and final xor to zero and unclick any reversals. The result for both is 89a1897f (in hex).