---
title: "Ethernet Communication Problem With W5500 MACRAW"
url: "https://maker.wiznet.io/forum/14493"
markdown_url: "https://maker.wiznet.io/forum/14493/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Mert Gulsoy"
created: "2022-03-04T11:41:27+09:00"
last_activity: "2022-03-23T14:50:21+09:00"
language: "en"
views: 778
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Ethernet Communication Problem With W5500 MACRAW

## Question

Asked by Mert Gulsoy on 2022-03-04 in Ethernet Chips.

Hi,

I have designed a device using W5500 chip as network interface. The problems I have are these:

- Auto negotiation does not work. I have to set the **PHYCFGR** register **OPMD** and **OPMDC** bits manually to the 10MB Full Duplex or Half duplex. When I set the mode to 10MBit *-duplex. Device detects link and link led flashes. Also PHYCFGR register shows correct state meaning link is up. I thought this may be related with the switch but I have some Chinese w5500 modules and they work well with the same switch and the same setup. I mean auto-negotiation works with Chinese modules.

- When I try to send packets **MACRAW**, link and activity leds go off for some seconds. And then comes back but no packet is sent as I check with wireshark.

- I configure Interrupts, activate **SENDOK** interrupt and then try to send **MACRAW** packet. First packet causes the link and activity leds go off and some seconds later they come back. Although i see leds go off device asserts int pin and **Sn_IR** register shows **SENDOK**. When I continue to send packets leds stay normal, w5500 issues **SENDOK** but nothing received on the other end. (Wireshark)

- Although no MAC filter is set, and the activity led blinks, device receives nothing. The register **Sn_RX_RSR** is always 0.

- Edit: By comparing the Chinese W5500 chip with the one on my design, the W5500 chip on my design gets hotter than the Chinese module W5500.

As a summary: I can talk with the W5500 via SPI but W5500 does not talk with ethernet.

My Setup:

- MCU: Atmel Sam4s, arm cortex M4 at 120Mhz.

- SPI: 4 MHz

- My design is a copy of the reference schematic in wiznet wiki.

**Schematic**

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/d/d6e4d571ba0354fbb15d7a3fd3b303c099cc9676.png) image2338×1653 63.4 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/d/d6e4d571ba0354fbb15d7a3fd3b303c099cc9676.png)

**Layout**

[![image](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/5/547795e7a1bdeb4f6c85adf67fc6c5a724261f34.png) image1465×658 142 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/5/547795e7a1bdeb4f6c85adf67fc6c5a724261f34.png)

There is copper pour ın both sides except under the rj45 jack.

I would appreciate any help.
Thank you.

## Replies

### Reply 1 by Mert Gulsoy, 2022-03-23

No Ideas? Nobody?

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Source: https://maker.wiznet.io/forum/14493