SPI Read errors on W5500

TCP/IP Chip W5500
1

I’ve started using a W5500 on a WIZ850io board. I am using a microcontroller to talk to the W5500 over the SPI. I can write and configure the device, but when I read back I get errors on two out of every four bytes (when bit 1 is set to 1). Example - set Common Register Block to: mode 00, Gateway address 192.168.1.1 (C0.A8.01.01), Subnet mask 255.255.255.0 (FF.FF.FF.00), SHAR 00.08.DC.01.02.03
Expected:
00 C0 A8 01 01 FF FF FF 00 00 08 DC 01 02 03
Read:
00 C0 02 02 01 FF FE FE 00 00 B8 B8 01 02 81 81 etc
The writes are correct as I can Ping the IP address and an ARP request shows the configured hardware address. But the error stops me reading many status registers (PHYCFGR, S0_SR etc). I haven’t tried reading the Rx buffer, but I expect the same result.
I get the same result on two W850io boards. Any suggestions as to what could be wrong?

2

The minimum guaranteed speed of the SCLK is 33.3 MHz which was tested and measured with the stable waveform.
Therefore you need to confirm the used SPI Clock frequency.

3

The microcontroller is running an 11MHz Clock with SPI interface set to half rate. I may have found the problem myself. Connecting a logic analyser to the SPI pins resolved the issue. Disconnect, and it returns. I need to look at the connections better. Thanks for you reply.

4

thanks my issue has been fixed.

5

thanks for the awesome information.