How Do I Control the Number Of Bytes For Single Bit Write and Dual Bit Write?

Question from the Customer:Question from the Customer:

I am using the Promira Serial Platform to communicate on my SPI bus.  I’m using the SPI Active - Level 2 Application. I need to perform an SPI dual bit mode write at 20MHz as a master. The specifications show I can do this – I’d like to find out more about the flexibility and programmability.

For example, is it possible to specify how many bytes in single bit write before switching into dual bit write? Here’s a diagram of what I’m planning to do.

161054-customer-chartFor example, in a total of 103 bytes, the first 3 bytes is single bit IO and next 100 bytes are dual bit IO. How can I do this?

Response from Technical Support:

Thanks for your question! It is possible to accomplish this with the Promira Serial Platform and the SPI Active – Level 2 Application that you purchased.  You can specify the IO type (Single/Dual/Quad) for every byte sent on the wire as a master.  (Please note, Quad IO is only available with the SPI Active – Level 3 Application.) There are two ways you can do this:

Control Center Serial Software
To try it initially, you can use the Multi I/O mode in Control Center Serial Software  - you can specify the IO mode for bytes at different stages. Here is an example:


For details, we have a Knowledge Base article you can refer to - Programming a Dual SPI Flash Using the Promira Serial Platform and the Control Center Serial Software using Multi I/O SPI.

Promira Serial Platform API
For greater flexibility, we recommend using the Promira Serial Platform API, which supports multiple platforms, and you can use Queue SPI Master Write (ps_queue_spi_write). The API Queue is a command that writes a stream of words to the downstream SPI slave device taking in the SPI IO Mode, (PS_SPI_IO_STANDARD/PS_SPI_IO_DUAL/PS_SPI_IO_QUAD) as one of the arguments. For more information about API, please refer to Promira API Documentation.

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

More questions? More ideas? You can also contact us and request a demo that applies to your application, as well as ask questions about the Promira Serial Platform and other Total Phase products.

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