W6100 last byte becomes first


I have a quite strange problem. I send a message ‘12345678’ to the W6100 and then read form it’s buffer ‘81234567’. I just always have my last byte on the first position. If I continue sending this message I continue recieving the same result, I mean ‘81233456781234567’.

Could you help with this problem, please?

Hi. I am new to the W6100 and about to start some new designs with this controller but thought to ask - could this be due to an internal cyclic buffer?

What if you write “1234567” and read this back - what is the result?


Did you check the real packet with wireshark capture program?
W6100 data communication is already proven.
It maybe your mistake. can you share your code?

Thank you.

Thank you for your help!

You were right, It was my mistake. My MCU operates with 80 MHz frequency, so I was sure, that there shouldn’t be any problem with bus communication with 100 MHz Wiznet. I just increased timings and now it works properly.