What is the Fastest Way I Can Switch from an I2C Master I2C to I2C Slave using the Aardvark I2C/SPI Host Adapter when Testing I2C Devices?

Question from the Customer:

I am using Aardvark I2C/SPI Host Adapter, and I’ve come to a stage in the project where I could use your help.  I’m testing SMBus/I2C devices running at 400 kbps. This test includes logging the following steps (which are repeated):

  1. As an I2C Master, I need the Aardvark adapter to transmit an I2C sequential write of less than 128 bytes, to a slave device at 7-bit slave address X
  2. To respond to 7-bit slave address Y, I need the Aardvark adapter to immediately switch its mode to I2C Slave. Swapping from Master to Slave, I need the delay to be no more than 30 us.
  3. The I2C sequential write will be less than 128 bytes, which will occur about 100 us after transmitting from step 1
  4. Save and process the received message.

Here’s what it looks like:

Timing diagram:  Switch from an I2C Master I2C to I2C Slave Do you have a device that can alternate Master/Slave modes that quickly?  What are my options?

Response from Technical Support:

Thanks for your question! Taking a look at your specifications, our adapters do not switch modes that quickly – however, we have a solution for you. Our recommendation, which is both effective and low-cost, is using two Aardvark adapters: one adapter set up as the Master, the other adapter set up as a Slave.

To maximize the speed of looping your test, we also recommend using the Aardvark Software API, which is provided with functional examples that you can use as-is or modify for your specifications, as well as create your own scripts. For details about API calls, please refer to the I2C Interface commands in the API Documentation section for the in the Aardvark I2C/SPI Host Adapter User Manual.

Additional resources that you may find helpful include the following:

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.

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