---
title: "Don't work Parallel Bus Mode"
url: "https://maker.wiznet.io/forum/13458"
markdown_url: "https://maker.wiznet.io/forum/13458/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "alex644"
created: "2019-08-28T00:29:53+09:00"
last_activity: "2019-08-28T00:29:54+09:00"
language: "en"
views: 658
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Don't work Parallel Bus Mode

## Question

Asked by alex644 on 2019-08-28 in Ethernet Chips.

I bought a W5100S chip and built my own custom board with it. Schematics is an exact copy of the schematics provided by Wiznet. Interface Mode is selected by MOD [3: 0], I have selected “010X”: Parallel Bus Mode. I can’t read any of the registers. In accordance with section 7.4.2. I configured the interface and tried to read the register “MR” at 0x0000. Result 0x03.
I tried to read other registers, I always get the result 0x03. What could be the problem?

[![1](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/f/f4542103e69736283e44939219ecbb4a8ef2d89c.png) 11288×1032 90.3 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/f/f4542103e69736283e44939219ecbb4a8ef2d89c.png)

[![2](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/0/0cc7dd56c3a7410b2de3cbd516fa907a2d5ccf9d.png) 21288×1032 90.1 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/0/0cc7dd56c3a7410b2de3cbd516fa907a2d5ccf9d.png)

---

Source: https://maker.wiznet.io/forum/13458