I have been using the Cheetah SPI Host Adapter as an SPI Master – now I need the functions of both an SPI Master and an SPI Slave. I see the Cheetah adapter only functions as an SPI Master.

For ease of use, I’m looking to use the same model for these functions. I need to operate these SPI devices independently on a PC, without having to “toggle” between the two devices.

• What are your recommendations?
• Also, in SPI Slave mode, can the adapter send data to the SPI Master Device in “normal” SPI communication?

Thanks for your question! Both the Promira Serial Platform and the Aardvark I2C/SPI Host Adapter can function as either a Master or a Slave device for SPI. Following is a summary of what both tools can do for you.

Summary of Master / Slave Emulation

Two Promira platforms, as well as two Aardvark adapters, can operate from one computer. They will each need a software interface, such as an instance of Control Center Serial Software, for each tool. Neither tool can change their role as Master or Slave “on the fly”.

Because you have been using the fast and powerful Cheetah adapter, we recommend the Promira platform for comparable performance levels.

Advantages of the Promira Serial Platform

In addition to higher clock speeds, the Promira platform provides many built-in advantages over the Aardvark adapter:

• Integrated level shifting from 0.9 to 5.0 volts
• Provide a total of 200 mA of power to target devices
• High-speed USB connectivity to the host system
• Ethernet connectivity, which supports remote control. For information about setting up the Promira platform for Ethernet connectivity, please see this article: To Run SPI Tests at a Higher Speed, How Do I Set Up Ethernet Connectivity and the Async Queue for the Promira Serial Platform?
• In master mode, configure Slave Select (SS) polarity
• Support for up to 8 slaves (dependent upon level of application licensed)

You will need the appropriate Active level application for your setup. Each application is licensed separately, and level 2 and 3 applications require licensing the previous level of application.

SPI Active - Level 1 Application

• Clock speed up to 12.5 MHz for Master functionality
• Clock speed up to 8 MHz for Slave functionality
• Supports two GPIOs
• One slave select
• Supports Single I/O SPI

SPI Active - Level 2 Application

• Clock speed up to 40 MHz for Master functionality
• Clock speed up to 20 MHz for Slave functionality
• Supports up to 12 GPIOs
• Supports up to three slave selects
• Supports Single and Dual I/O SPI

SPI Active - Level 3 Application

• Clock speed up to 80 MHz for Master functionality (faster than the Cheetah adapter)
• Clock speed up to 20 MHz for Slave functionality
• Supports up to 16 GPIOs
• Supports up to eight slave selects
• Supports response size of up to 256 bytes
• Supports Single, Dual, and Quad I/O SPI

Comparing the SPI Tools

For an easy comparison, here’s a table that shows you the primary features of the Aardvark and Cheetah adapters versus the Promira platform with the Active applications:

We hope this answers your questions. Additional resources that you may find helpful include the following:

• Promira Serial Platform I2C/SPI Active User Manual
• Aardvark I2C/SPI Host Adapter
• Cheetah SPI Host Adapter User Manual
• Choosing the Right Total Phase Host Adapter
• Basics of the SPI Communication Protocol
• SPI – Serial Peripheral Interface

If you have questions about our Total Phase products, feel free to email us at sales@totalphase.com. You can also request a demo that is specific to your application.