Bus Analyzer, Monitor, Debugger and Programmer

In the world of rapidly accelerating product development cycles, engineers developing products which utilize the I²C and SMBus interfaces need a bus analyzer that is easy to use—fast and simple.

Unforeseen problems such as functional bugs can cause schedules to slip so it is important to have the right tool to resolve them quickly by isolating the root cause.

The Corelis BusPro-I analyzer is designed with that idea in mind—the right tool at the right price. Open the box and plug it in; everything just works.


  • Supports I2C and SMBus
  • Supports Standard-mode, Fast-mode, and Fast-mode Plus (Fm+) with I2C bus data rates up to 5 Mbit/s
  • Supports High-speed mode (Hs-mode) monitoring up to 5 Mbit/s
  • Passive traffic monitoring with unlimited state and timing recording
  • Time stamping, message filtering, and symbolic translating
  • Programmable trigger event to highlight bus transactions of interest
  • Automatic detection of bus voltage and signal thresholds
  • Two general purpose I/O channels
  • Programmable bus voltage reference and software configurable pull-up resistors on the SDA and SCL lines
  • In-System Programming of I2C serial EEPROMs
  • High-speed USB 2.0 interface
  • Robust and portable bus-powered USB device, no external power supply required
  • 32- and 64-bit APIs for integration with third party languages, including Python and LabVIEW
  • I2C Exerciser software supports Microsoft Windows 7, Windows 8/8.1 and Windows 10 operating systems


The BusPro-I is an entry level, yet feature-packed and robust I2C debugging tool. The BusPro-I allows engineers to save precious development time by providing low level visibility and control of an I2C bus. There is no longer a need to hook up a logic analyzer to capture traffic on the bus and then spend hours sifting through mountains of data in order to find that one particular bit. The Core-lis hardware and software provide a convenient and intuitive environment for hardware debugging, software development, and in-system programming.

I2C Monitor

Passively listens and records all I2C bus traffic while displaying real-time data in both state and waveform timing windows. By using the computer hard drive for trace storage, the BusPro-I has virtually unlimited trace data recording capability. message filtering, symbolic translation, and event triggering are all included. During capture, bus signal validation and protocol conformance are continually evaluated with deviations flagged. An example screenshot of the monitor window is shown below.

I2C Exerciser Monitor Screen 1 - BusPro-I I2C Bus Analyzer

I2C Exerciser Monitor Screen

I2C Debugger

A user interactive bus I/O access portal. The debugger enables individual bus transfers for immediate target communications. Looping supports repeated I/O patterns to facilitate external signal observations. Besides generic writing and reading of data blocks, a growing library of standard devices is included showing interactive screens tailored to the device’s organization (such as ADCs, DACs, flash memories, SMBus behavior, etc.). An example screenshot of the debugger window is shown below.

 CAS 1000 I2CE Debugger Window - BusPro-I I2C Bus Analyzer

BusPro-I Debugger Window

I2C Programmer

Provides easy-to-use high-speed in-system programming of I2C-compatible serial EEPROMs. Two example screenshots of the programmer windows are shown below.

I2C Programmer

BusPro-I Programmer Window

I2C Programmer

BusPro-I Programmer Read Device Contents Window


At the core of the BusPro-I is an on-board engine whose logic performs the low level interaction with the I2C bus. This element receives set-up, direction, and drive data from the host via a USB 2.0 port. Conversely, as bus activity is detected and characterized, its transitional information is conveyed up to the host for further processing.

Test Discrete I/O Signals

Two programmable lines can be operated under PC host software control. They are available to stimulate the target system or sense target conditions in coordination with the testing. Each line is programmable as input, output, or output open-drain. One of these outputs can be used as a dedicated trigger to synchronize with external laboratory equipment. A second discrete I/O can be used as an input trigger.

Adjustable Voltage Levels

The voltage levels of the discrete I/O and trigger lines are programmable from 1.25V to 3.3V in increments of 50mV. The I2C bus reference voltage can be programmed as target driven through its bus pull-ups or driven from the BusPro-I analyzer. This target reference voltage can also be measured. When the BusPro-I is programmed to source this reference level, the voltage can be set with 100mV resolution over the range of 0.8V to 5V. When the BusPro-I reference voltage drives the bus, one of a set of pull-up resistors can be selected. The resistor values span the range from 250 to 50K ohms. Additionally, individual threshold levels can be adjusted for sensing high and low conditions on the bus. This supports I2C bus hysteresis requirements.

Adjustable Voltage Levels

BusPro-I Hardware Configuration Window
* Note: The I2C bus is also often referred to as IIC bus, Philips I2C bus, Inter-IC bus, 2-wire bus, 2-wire serial bus, two-wire bus, or SMBus.

Hardware Specifications

Mechanical Dimensions5.50 x 1.00 x 4.75 (+/- 0.10) inches
Shipping Weight2 pounds (approximate)
CertificationsRoHS Compliant, CE Marked
USB Interface
USB Transfer RateHigh-speed USB 2.0
USB CableShips with a 6 foot USB 2.0 A to B cable
Column 1 Value 3Column 2 Value 3
I2C Interface
I2C Bus ConnectorRJ45 (AMP P/N 406549-1)
I2C Bus CableShips with a 12 inch interface cable that terminates in flying leads suitable for connection to 0.025 inch square posts. Test clips are also included.
BusPro I 300x222 - BusPro-I I2C Bus Analyzer


busanalyzercomparisonbannr1 - BusPro-I I2C Bus Analyzer
ecereaderaward1 - BusPro-I I2C Bus Analyzer

Advanced Feature Sets

For engineers requiring an I2C tool with even more advanced feature sets, Corelis offers the CAS-1000-I2C/E. This advanced unit provides significantly enhanced functionality such as I2C compliance testing, master and slave emulation, bus parameter measurement, glitch injection, clock stretching and adjustable timing skew.

BusPro-I Case Study

This BusPro-I Whitepaper provides an overview and case study of how the BusPro-I can debug an I2C interface, quickly identifying the issue and ultimately allowing it to be fixed.


Software Development

Monitor and log I²C bus traffic in real-time

Hardware Debugging

Generate traffic to exercise the bus and communicate with its peripheral components

In-System Programming

Read, erase, program and verify I²C serial EEPROMs


Monitor displays high-level view of I2C bus traffic. Bit and protocol level information is also available and graphically displayed as a timing waveform.

Debugger allows direct read/write access to peek and poke device registers on the I2C bus. The BusPro-I acts as a master to generate I2C transactions while simultaneously monitoring the traffic on the bus.

I2C Exerciser software is easy to learn and use. Graphical interface allows quick access to the powerful functionality and filters out the noise so that you may focus on the trace data that you actually need to see.

Everything needed to get started is provided. No need to purchase additional “optional” modules or adapter cables to be compatible.

Ordering Information

Part Number 90010

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