W5500 - can't open socket

Question

Hi everyone, me need help. I trying write DHCP client for gathering IP address but i can’t open socket in UDP mode (as in any other mode). My steps (between steps has delay ~300ms): Connect Ethernet cable and power up; Hardware reset using RST pin – OK; Read Chip ID register and check value (0x04) – OK; Software reset by write value 0x80 to Mode Register – OK; Wait until RST bit is reset – OK; Check PHYCFGR register value - get 0xBF, link UP – OK (may be); Write 0x0044 value to S0_PORT register – OK; Read value from S0_PORT register and compare with written value (0x0044) – OK; Write 0x02 value to S0_MR for UDP mode – OK; Read value from S0_MR register and compare with written value (0x02) – OK; Write 0x01 value to S0_CR for open socket – OK; Read value from S0_CR register and compare with 0x00 (command accepted) – OK; Read value from S0_SR – always read 0x00. Why? I tried this steps for all sockets – can’t open no one. I write to registers using 1MHz SPI speed in SPI_MODE0 (MSB first) and Variable Length Data Mode. I tried using Fixed Lingth Data Mode – without changes. I don’t use some library – only direct write to registers using simple SPI driver. Also i tried setup static IP address (gateway, mask, source IP) and using ping tool for check W5500 working. W5500 answer on ping requests. Also i noticed strange behavior with RST bit in PHYCFGR register. After write RST bit to 0 it is not never set to 1, LEDs on Ethernet connector is disabled. After write RST bit to 1 using SPI – LEDs on Ethernet connector is blinks. It is nornaly? Please, help me. I don’t have no idia :(. I have two W5500 and both don’t work.

Eugeny · Answer

NeoProg: Read Chip ID register and check value (0x04) – OK; Software reset by write value 0x80 to Mode Register – OK; Wait until RST bit is reset – OK; Would it be better to perform software reset and only then try reading the chip ID? I do not think it is much difference, but I would prefer this way. NeoProg: Read value from S0_SR – always read 0x00. Why? Good question. Did you set up source MAC address, proper source IP address and mask? Anything in gateway address? NeoProg: After write RST bit to 0 it is not never set to 1 Datasheet does not say it will return back to 1 automatically. It says this bit must be set to 1 after setting it to 0 (for proper PHY operation).

Eugeny · Answer

Sounds like workflow problem. And you are right, MAC address must be sufficient. Can you please set port number after setting Sn_MR to 2?

NeoProg · Answer

Sorry, problem was in broken wires for demo board power supply. After resplace wires W5500 work correctly and i can open socket! I should have checked power using oscilloscope before search problem in code. I did school mistake again Thanks for help, Eugeny. Have a nice day.