---
title: "PHY Registers"
url: "https://maker.wiznet.io/forum/14623"
markdown_url: "https://maker.wiznet.io/forum/14623/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Welocs"
created: "2022-08-23T09:39:16+09:00"
last_activity: "2022-08-24T10:36:51+09:00"
language: "en"
views: 344
replies: 3
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# PHY Registers

## Question

Asked by Welocs on 2022-08-23 in Ethernet Chips.

Hello,

in the W6100s datasheet, there is a chapter “6.8.6 Ethernet PHY’s Registers Control”.

But in the datasheet nor on the W6100s-github/website i didn’t find any information about what these registers are and do.
Did i miss something/some document?

Regards

## Replies

### Reply 1 by Eugeny, 2022-08-23

Maybe [this](https://github.com/Wiznet/io6Library/blob/master/Ethernet/W6100/w6100.h#L3076) will help.

### Reply 2 by Welocs, 2022-08-24 (in reply to reply 1)

Yeah, thank you, this give me some idea of these registers. From this header file, it looks like there is not really something to control, and if so, you can control it via the PHYCR0 and PHYCR1 registers.

[@Wiznet](https://maker.wiznet.io/u/wiznet): it would be nice, if you could bring out a documentation for this ![:slight_smile:](https://emoji.discourse-cdn.com/twitter/slight_smile.png?v=12)

Regards

### Reply 3 by Eugeny, 2022-08-24

![](https://avatars.discourse-cdn.com/v4/letter/w/b9bd4f/48.png) Welocs:

> you can control it via the PHYCR0 and PHYCR1 registers.

Maybe those registers just useless for regular use, and we just do not need to touch them after properly resetting the PHY. Why they documented these registers? Maybe having some bigger plans!

---

Source: https://maker.wiznet.io/forum/14623