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Support Question of the Week: How do I set up the Beagle I2C/SPI Protocol Analyzer to analyze a 1.8V I2C device with the Level Shifter Board?

We have a BeagleTM I2C/SPI Protocol Analyzer and are using it with the Level Shifter Board. The target is a 1.8V I2C device and we're trying to set it up with an external power supply - not provide power from the Beagle analyzer. We believe we have it set up correctly, but the Data CenterTM Software shows no activity. Our setup is as follows:

  •  The TPWR jumper is removed.
  •  All voltage level jumpers removed.
  •  The TP240411 10-Pin Grabber Clip Split Cable is connected to the TARGET1 header.
  •  The Beagle analyzer is connected to the Analyzer header.
  •  To the target, SDA and SCL are straightforward.
  •  To power the target side of the level converter board, the NC/+5V grabber is connected to the target's 1.8V supply.

The NC/+5V grabber does have continuity with the TPWR pin at the EXT TGT header area on the Level Shifter, and an oscilloscope shows activity on the SDA and SCL lines, and 1.8 VDC on pin 4 and pin 6 of the TARGET2 header. However, the TARGET LED is not turned on, and the Data CenterSoftware shows no activity. Can you advise us what to look for to troubleshoot this?


Level Shifter Board Supports Fast SPI Signals and SPI Functions: Master, Slave, and Monitor Figure 1: Level Shifter Board


Thanks for your question! Your description indicates that the setup correct. The SCL and SDA lines go through the Level Shifter, on which the TPWR pin on the EXT TGT header (pin 13) is connected to the target side of the device. The TPWR is also connected to the TARGET1 and TARGET2 connectors (pins 4 and 6). When properly connected, the TARGET LED illuminates amber.

The one step not described in the setup is enabling the Beagle's target power to provide power to the analyzer side of the level shifter board. This can be verified by looking at the Power LED, which must be lit green. The Level Shifter Board will not work if  the LED is not lit green - the TPWR jumper isolates the analyzer side from the target side power. For more information, please refer to section 3.4 of the Level Shifter Board User Manual.

In the Data Center Software, ensure I2C "Target Power" of the Beagle I2C Protocol Analyzer is selected. For more information about I2C device settings, please refer to section 7.2 of the Data Center Software User Manual.


Enable Beagle I2C Protocol Analyzer Target Power in Data Center Software Figure 2: Check "Target Power"  in Data Center Software


For more information, please refer to the following documents.
Level Shifter Board User Manual
Data Center Software User Manual
Beagle Protocol Analyzer User Manual
Total Phase Products
Product Selector Guide

We hope this answers your question. If you have other questions about our host adapters or other Total Phase products, feel free to email us at sales@totalphase.com or submit a request for technical support.



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