---
title: "Uthernet II Snooper CDA"
url: "https://maker.wiznet.io/simons/projects/uthernet-ii-snooper-cda/"
markdown_url: "https://maker.wiznet.io/simons/projects/uthernet-ii-snooper-cda/md"
type: "UCC: User Created Content"
author: "ksherlock"
author_url: "https://github.com/ksherlock/u2snooper"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "ksherlock"
original_url: "https://github.com/ksherlock/u2snooper"
published: "2023-08-02"
language: "en"
hardware: ["WIZnet W5100"]
likes: 1
views: 283
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# Uthernet II Snooper CDA

> Uthernet II Snooper CDA

Original author: ksherlock (source: https://github.com/ksherlock/u2snooper)

## Components

- **WIZnet W5100** x 1 ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5100))

## Article

This is a Classic Desk Accessory to peek and poke at the Uthernet II/Wiznet w5100 registers.

Slot 3 is assumed.

Built with the SNASM assembler and [snlink](https://github.com/ksherlock/snlink), sorry.

Keys:

- C - Common registers

- 0 - Socket 0

- 1 - Socket 1

- 2 - Socket 2

- 3 - Socket 3

- R - Receive buffer

- T - Transmit buffer

- Left arrow, right arrow - switch between pages

- Up arrow, down arrow - scroll through memory (RX/TX only)

- : - write memory.

- Esc - quit

- Q - quit

Writing memory:

Format is `address : xx [xx ...]` where xx is a hexadecimal byte and address is 8-bit or 16-bit hexadecimal. spaces are optional.

For the socket registers, the page high-byte (`$00`, `$04`, `$05`, etc) is pre-loaded so an 8-bit address will work as expected. The display will be reloaded after a write but keep in mind some registers are not visibly changed until a command is entered (eg, tx write doesn't update until a send command).

Be careful writing the MR register ($00) :-)

---

Source: https://maker.wiznet.io/simons/projects/uthernet-ii-snooper-cda/