How Can I Use the Aardvark I2C/SPI Host Adapter in Slave Mode with a Master I2C Device under Test?

Question from the Customer:

 I’m using the Aardvark I2C/SPI Host Adapter, and am trying to use it in slave mode to send data to an master I2C device under test (DUT). That I2C device cannot be setup as a slave – it only functions as a master.

How do I send data using the Aardvark adapter in slave mode? For other tests, such as validating the MISO line, is there any way I can use the Aardvark adapter in mode with the DUT?

Response from Technical Support:

Thanks for your questions! When the Device Under Test is a Master device, you cannot use any other master device to communicate directly to it. For that task, we recommend using a slave device, such as the Aardvark adapter, in slave mode. For more information about communication between I2C devices, please refer to the section I2C Background in the Aardvark I2C/SPI Host Adapter Manual and the NXP document, UM10204.

 Aardvark I2C/SPI Host Adapter

Figure 1: Aardvark I2C/SPI Host Adapter

The Aardvark adapter is a great tool for simulating a slave device. The Slave Response or read out data can be up to 64 unique bytes. The amount of data that can be written to the slave can be up to 4096 bytes. When reading from the Aardvark adapter, it will reply with as many bytes as the master device requests. The Aardvark adapter is capable of sending responses set by you, the user.  The Aardvark adapter in slave mode only supports a single response.

For example, if you set the response for 10 bytes in the slave configuration and the master requests 25 bytes to be read from the slave, the slave will reply with the unique 10 bytes twice and the first 5 bytes of the 10 byte response in order to meet the Master's read of 25 bytes.

We recommend using the Total Phase Control Center Serial Software or the Aardvark Software API. Control Center Serial Software is an easy to use tool – allowing you quick and easy use of the I2C, SPI, and GPIO functionalities of the Aardvark adapter. With the API software, you can create custom programs for your specifications. Functional program examples are provided that you can use as-is or modify as needed.

Additional resources that you may find helpful include the following:

We hope this answers your questions. If you have other questions about our host adapters or other Total Phase products, feel free to email us at, or if you already own one of our devices and have a technical question, please submit a request for technical support.

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