--- title: "SPI Read errors on W5500" url: "https://maker.wiznet.io/forum/14198" markdown_url: "https://maker.wiznet.io/forum/14198/md" type: "Forum topic" category: "Ethernet Chips" author: "Gabbro" created: "2021-03-24T16:39:58+09:00" last_activity: "2021-12-25T12:10:13+09:00" language: "en" views: 1010 replies: 4 source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)" --- # SPI Read errors on W5500 ## Question Asked by Gabbro on 2021-03-24 in Ethernet Chips. 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? ## Replies ### Reply 1 by irina, 2021-03-24 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. ### Reply 2 by Gabbro, 2021-03-25 (in reply to reply 1) 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. ### Reply 3 by jackyjoy123, 2021-08-11 thanks my issue has been fixed. ### Reply 4 by jackyjoy123, 2021-12-25 ![](https://avatars.discourse-cdn.com/v4/letter/j/d6d6ee/48.png) jackyjoy123: > thanks my issue has been fixed. > [creditcardsupportx.com - This website is for sale! - creditcardsupportx Resources and Information.](https://creditcardsupportx.com/barnes-and-noble-barclay-mastercard) > [creditcardsupportx.com - This website is for sale! - creditcardsupportx Resources and Information.](https://creditcardsupportx.com/target-red-credit-card) thanks for the awesome information. --- Source: https://maker.wiznet.io/forum/14198