---
title: "W5100 socket1,socket2 and socket3 Sn_RX_RSR problem"
url: "https://maker.wiznet.io/forum/11556"
markdown_url: "https://maker.wiznet.io/forum/11556/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "mustafaozturk"
created: "2015-12-29T06:36:28+09:00"
last_activity: "2017-05-04T08:37:52+09:00"
language: "en"
views: 510
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W5100 socket1,socket2 and socket3 Sn_RX_RSR problem

## Question

Asked by mustafaozturk on 2015-12-29 in Ethernet Chips.

Hi all

İ tray to open socket(0) UDP mode --its work fine.But when i open socket(1),socket(2) or socket(3) and after recieving data the Sn_RX_RSR register gives 0x0000 value always .I read the Socket recieve area from Base adress ,i see the valid data is recieved ,but Sn_RX_RSR register is not changed (it si allways 0x0000).Please help me ,what is the problem ?
Thanks

## Replies

### Reply 1 by Eugeny, 2015-12-29

Mustafa, most probably you read data from wrong location. For socket 0 regbase should be 0x400, for socket 1 it should be 0x500, socket 2 is 0x600 and socket 3 is 0x700. Thus RSR register locations are (for respective socket): 0x426/0x427, 0x526/0x527, 0x626/0x627 and 0x726/0x727 of W5100 absolute address space. Also ensure to read 0x**6 register first and only then 0x**7.

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Source: https://maker.wiznet.io/forum/11556