Communicating with the W5500io


I have a W5500io hooked up to a STM device, and I’m sending it messages to ask for the MAC address and gateway address but don’t seem to be getting a valid response. I also can’t find any reference in any documentation to the SPI speed I should be using. I currently have mine set at 42MHz. Is that too fast?

My message looks like this:


W5200 SPI speed is upto 80MHz. But, It’s speed depends on PCB and any noise.

The picture can’t show that SPI CLK consists on 4 phase for 2bytes address, 1bytes control and 1bytes data.

First, You will try to verify read 0x04 value from VERSIONR at 0x0039.
For more detail, refer to



Hello, jdcowpland,

I met the same problem as you did. (using SPI to set gateway, ip, mac. etc)

I checked that the data format is right, (2 bytes offset address, 1 byte control code and then data) but I can not receive the response of W5500, the MISO pin is always 1 (according to the pull-up resisitance).

Have you solved your problem, and would you like to share your experience?




In your captured SPI interface, The clock of Address & ControlI Phase existed. But I couldn’t find the SCLK for DATA phase.

Check the SPI clock generation.

Thank you.


I am intrigued by the diagram. What tool did you use for that?