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Which Tool Should I Use to Have One SPI Master Control Multiple Chips on an SPI Bus?

Question from the Customer:

We plan to use a host adapter to exercise a target board that we are developing. This board has two chips on an SPI bus.  The setup includes a second board (that we are also developing) that will connect to the host adapter and pass the SPI to the target board.

We need a tool that supports two chip select lines for the two chips on the target board.  We are looking to manually pump out data to each of our target chips. That’s really all that we need to do - the exercise we’ll do with the target board is very simple. What do you advise for controlling an SPI bus with multiple chips?

Response from Technical Support:

Thanks for your question!  For an easier method, we suggest using either the Cheetah SPI Host Adapter or the Promira Serial Platform with the SPI Active – Level 2 Application.  Both tools support 3 slave selects. For the simplest usage, we recommend using the Promira Serial Platform with the Control Center Software. It supports communicating with multiple slaves through the GUI.  You can also use it in batch mode to send a sequence of commands without writing code.

 Promira Serial Platform  Cheetah-250

Figure 1: Promira Serial Platform

Figure 2: Cheetah SPI Host Adapter

How to use the Control Center Serial Software for multiple slaves

Setting up which slave to access and sending commands is easy:

  1. Connect the Promira Serial Platform to the Control Center Software.
  2. At the top menu bar, select Adapter and then click Multi I/O SPI.
  3. In the Multi I/O SPI window, select the SSn for the desired slave. The number of displayed Slave Select lines is dependent on how many slaves the attached device can support. You can also select the desired Bitrate.
  4. Set the command and address values.
  5. There is large text box that for inserting the data you want to send . Transactions are displayed below in the Transaction Log.
Control Center Serial Software - Multiple IO Figure 3: Control Center Serial Software – Multi I/O SPI dialog
About the Cheetah SPI Host Adapter and the Promira Serial Platform:

Here is a summary of the capabilities of the Cheetah adapter and the Promira platform. Note that the Promira platform can function as either Slave or Master, and that applications are available to support SPI and I2C bus operations, as well as eSPI Action and eSPI Analysis. The Cheetah adapter functions only as an SPI Master.


Promira Applications Comparison Chart


Note - for the Promira platform, to use the SPI Active – Level 2 Application, the SPI Active – Level 1 Application is required.  For SPI Active –Level 3 Application, both Level 1 and Level 2 applications must be installed.

Additional resources that you may find helpful include the following:

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 if you already own one of our devices and have a technical question, please submit a request for technical support.