Question from the Customer:
I need to program and monitor an SMBus device. Which Total Phase instruments could I use for this project?
Response from Technical Support:Thanks for your question! The System Management Bus (SMBus) protocol is a derivative of the Inter-Integrated Circuit (I2C) protocol. Because of their similarities, our I2C host adapters and I2C protocol analyzer can be used with your SMBus project.
Comparing I2C and SMBus Protocols
I2C and SMBus are both 2-wire buses using a master and addressable slaves. SMBus is primarily used on PC motherboards and in embedded systems for monitoring critical parameters such as voltage supply, temperature, and fan control.
There are some differences about what these two protocols support and how they function. Both buses support a bitrate of 100 kHz, however I2C does support higher speeds so compatibility is only available below 100 kHz. Additionally, SMBus specifies a minimum clock speed and 35 ms timeout interval, while the I2C bus can hold the clock low as long as necessary.
For more information on these differences, you can take a look at these articles:
I2C Tools that Work with SMBus Devices
Here is a table so you can quickly compare the Total Phase devices that support I2C. (Note: the Cheetah SPI Host Adapter only supports the SPI protocol). The other tools can support both I2C (SMBus) and SPI protocols.
Following is a summary of the Total Phase devices that can support your project.
I2C and SMBus Host Adapters
We have two host adapters that are compatible with the SMBus.
Aardvark I2C/SPI Host Adapter
The Aardvark I2C Host Adapter is a fast and powerful bus host adapter that communicates with your computer via USB, and can function as a Master or a Slave. In addition to I2C and SMBus devices, this adapter also interfaces with SPI buses.
Promira Serial Platform
The Promira Serial Platform is an advanced platform that can communicate faster via Ethernet or USB, provides built-in level shifting, and more. The license options (purchased separately) support a range of protocols. For your project: I2C Active - Level 1 Application is recommended. The Promira platform can function as an I2C Master or I2C Slave.
I2C and SMBus Protocol Analyzer
The Beagle I2C/SPI Protocol Analyzer can be used to monitor and capture real-time I2C data. The Data Center Software offers SMBus decoding when using the Beagle I2C/SPI analyzer. To enable SMBus decoding, select the SMBus Decoding option in the I2C Configuration Manager dialog. For more details on how to decode SMBus transactions in the Data Center Software, please see the SMBus section 8.5.2 in the Data Center Software User Manual.
Other SMBus Tools
Test and Development
- With its I2C Port Expander, the I2C/SPI Activity Board can be used to test and develop SMBus devices.
- The I2C Development Kit includes the activity board as well as the Aardvark I2C/SPI Host Adapter, the Beagle I2C/SPI Protocol Analyzer, and cables. This is a powerful and cost-effective way to start a new project.
Software Applications
- Our Control Center Serial Software application provides easy access to the features of functions of the Aardvark adapter and the Promira platform.
- The Data Center Software application can be used with the Beagle analyzer. It is an easy to use GUI to set up conditions to monitor and capture data.
- If you need to customize your setup, API software is available: Aardvark Software API, Beagle Software API, and Promira Software API I2C/SPI Active. Several operating systems and programming languages are supported, and functional examples are provided that can be used as is or modified for your specifications.
Using Our Tools with SMBus
In addition to the information in the user manuals, here are two examples of using our tools with the SMBus:
- How Do I Debug SMBus Communication between my Aardvark I2C/SPI Host Adapter and a Smart Battery Pack?
- Support Question of the Week: How do I Communicate with an SMBus Slave Device using a Master I2C/SPI Host Adapter and the Control Center Software?
Additional resources that you may find helpful include the following:
- Aardvark I2C/SPI Host Adapter User Manual
- Beagle Protocol Analyzer User Manual
- Promira Serial Platform I2C/SPI Active User Manual
- I2C/SPI Activity Board User Manual
- Control Center Serial Software User Manual
- Flash Center Software User Manual
We hope this answers your question. Looking for more information? You can contact us and request a demo that applies to your application, as well as ask about our Total Phase products.