---
title: "Trouble Reading SPI Data W5500"
url: "https://maker.wiznet.io/forum/15377"
markdown_url: "https://maker.wiznet.io/forum/15377/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "atkrag"
created: "2024-12-05T05:46:57+09:00"
last_activity: "2024-12-05T05:49:04+09:00"
language: "en"
tags: ["W5500"]
views: 2
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Trouble Reading SPI Data W5500

## Question

Asked by atkrag on 2024-12-05 in Ethernet Chips.

Hello,

I am trying to interface a W5500 with my Infineon PSoC 6 MCU. I am having difficulty reading data from the W5500 registers over SPI. At some point, I send out data to the SHAR to set the local MAC address like this:

![](https://maker.wiznet.io/upload/ckeditor5/14538732%5F1733376988%2Epng)

I would then expect to see the same data bytes when I try to read from the SHAR, but all I get is 0x00 on the MISO line like so:

![](https://maker.wiznet.io/upload/ckeditor5/14538732%5F1733377133%2Epng)

I am using 0xFF as a dummy byte on the MOSI line to transfer data onto the MISO line from the W5500. I expect to see 0x00, 0x08, 0xDC, 0xAB, 0xCD, 0xEF here. Why do I only get 0x00?

In addition, perhaps someone could also explain why the W5500 puts 0x01, 0x02, 0x03 on the MISO line during the address and control phases? Is this intentional?

Your help is much appreciated, thank you.

## Replies

### Reply 1 by atkrag, 2024-12-05

Actually I just figured out my problem as I made this post haha! I forgot to set the write bit in the control phase for the write operations. This resolved my issue.

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Source: https://maker.wiznet.io/forum/15377