ENC28J60 SPI Transaction Analyzer

Overview

The ENC28J60 is a stand-alone Ethernet controller IC from Microchip Technology, designed for embedded applications. It features an integrated 10BASE-T Ethernet PHY, a full MAC layer, and internal buffer memory. One of its key advantages is the high-speed SPI interface, supporting clock speeds up to 20 MHz, allowing fast and efficient data transfer between the IC and a host microcontroller. This makes the ENC28J60 ideal for low-cost, network-connected systems such as IoT devices and embedded web servers.

The ENC28J60 SPI Transaction Analyzer is a high-level protocol extension for Saleae Logic 2, built to decode and interpret SPI communication between a microcontroller and the ENC28J60 Ethernet controller. By parsing commands, register accesses, and data transfers, the extension offers a clearer view of the communication process, making it easier to debug and verify Ethernet behavior at the protocol level.

---

How to use

Install

• Search for ENC28J60 SPI Transaction Analyzer in the Extensions tab (you’ll find it in the right-hand sidebar).
• If the extension doesn't show up in the search results, it might be because your extension catalog is out of date. In that case, simply click Check for Updates under More options (the icon with three dots).
• Click the Install button to install the extension.
• And that’s it - simple as that!

Configue

• First, add the built-in SPI analyzer to your capture, as this extension builds on top of it.
• Then, add SPI ENC28J60 as a new High-Level Analyzer.

• When the SPI ENC28J60 Settings window appears, set Input Analyzer to the SPI analyzer you just added.

• If everything is set up correctly, you should see decoded results like the example below:

• This is a tip for you: To make it easier to view the decoded results, it’s recommended to disable the SPI analyzer’s output in the Data section.

---

[Warning] Incorrect Capture Timing

• The ENC28J60 uses four register banks to organize its control registers. All banks share the same address space, and the active bank is determined by the value set in the ECON1 register (see Section 3.0 Memory Organization for more details).

• The label of the register being accessed is determined by looking up the argument together with the current_bank.
• This extension automatically sets the current_bank to BANK0 at two points: (1) when the capture starts, and (2) whenever a soft-reset command is detected.
• THEREFORE, IF YOU START A CAPTURE AT THE WRONG MOMENT, ALL DECODED DATA FROM THAT POINT ONWARD MAY BE INCORRECT. BE ESPECIALLY CAREFUL WITH THIS CASE!