Wiz550io Max SPI clock rate


Hi Wiznet support

What is the max SPI clock I can use with Wiz550io? I have got a Wiz550io Rev1.1 and it does NOT work if I use 24Mhz SPI clock, I get garbage data from W5500. My microcontoller only support max 24Mhz so I did not get a chance to test higher clock speeds but I doubt it would work above 24 either.

But if I reduce the SPI clock to 18 Mhz or below everything works Ok and I am able to run various TCP/UDP clients and servers without any problem.

From datasheet I know W5500 can support SPI speed upto 80Mhz. But on W550io the SPI clock to W5500 goes through the MUX so not sure if that is causing the bottleneck. Have you tested the max speed at your end ?

Please help.



Hi nver :slight_smile:

I tested the WIZ550io the using ioShield-A and Cookie board(CooCox).
I use 24MHz as SPI clock, It was no problem.
If you use the Jumper line between MCU and WIZ550io,maybe it don’t operate by noise.

ioShield-A URL : http://wizwiki.net/wiki/doku.php?id=osh:ioshield-a:start
Cookie board URL : http://wizwiki.net/wiki/doku.php?id=osh:cookie:start

EK :slight_smile: