---
title: "w5500 not working"
url: "https://maker.wiznet.io/forum/9481"
markdown_url: "https://maker.wiznet.io/forum/9481/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "akulcu"
created: "2024-09-29T00:17:25+09:00"
last_activity: "2024-09-29T00:17:25+09:00"
language: "en"
tags: ["W5500"]
views: 3
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# w5500 not working

## Question

Asked by akulcu on 2024-09-29 in Ethernet Chips.

Hello

I drew a circuit based on the WIZ550io-mini_V001 schematic in the attachment that I found on Wiznet's documentation site, connected it to an stm32 nuclo card and downloaded the wiznet library and made the necessary settings. I tried it with 2 different models of W5500 cards that I bought from the market to understand that the codes and the system worked, no problem.

However, when I tested the circuit I drew, it did not work at all.

In the first attempt
I drew the W5500 PMODE 0-1-2 pins as in the diagram to 3V3 and the RSVD pins to GND. In this case, it detected that the network cable was connected, but I could not get an IP address.

In the second attempt
I drew the W5500 PMODE 0-1-2 pins as in the diagram to 3V3 and left the RSVD pins floating. In this case, it did not even detect that the network cable was connected.

When I examined it a little, I came across very different applications.

1. In the attached WIZ550io-mini_V001 pdf, W5500 PMODE 0-1-2 pins are directly connected to 3v3 and RSVD pins are left floating.

2. W5500 Datasheet says to pull W5500 PMODE 0-1-2 up with 10K resistor and RSVD pins down with 10K.
Datasheet says to pull RSVD pins up with 10K resistor and NC is written opposite. Which one will we follow?

3. Both of the products I bought from the market work without any problems.
One of them pulled W5500 PMODE 0-1-2 pins directly to 3v3 and RSVD pins to GND.
In the other product, PMODE 0-1-2 up with 10K resistor and RSVD pins down with 10K.

PMODE 0-1-2 I will pull it up with a 10K resistor but
What should I do with RSVD? Should I leave it floating, should I pull it directly to GND or should I pull it to GND with a 10K resistor.

I am confused which one is correct, can you help me?

---

Source: https://maker.wiznet.io/forum/9481