Can the Promira Serial Platform Reduce Clock Cycle Gaps and Provide Precise Timing when Testing a New SPI Device?

Question from the Customer:
We’ve been using the Aardvark I2C/SPI Host Adapter for years – the software updates have been great, but now we’re testing a faster prototype SPI device. We need a faster adapter. Our goal: eliminate gaps between clock cycles.

Currently, there is a gap between each 8 clock cycles. For test harness purposes, to verify our device can sustain the desired bandwidth, we need to eliminate that gap and run at 50Mhz.

We’re thinking about using the Promira Serial Platform as an SPI master – can the delay between two bytes be removed to 0? For different setups, we will probably use Promira API Software and the Control Center Software.

Response from Technical Support:

Thanks for your question! Yes, the Promira Serial Platform can send bytes/words without any delay between them. The following table and diagram summarizes the AC Characteristics.

Table of AC Characteristics

Promira-SPI-master-AC-characterics

Timing Diagram of AC Characterstics

Promira AC Characteristics Timing Diagram

AC Characteristics and Timing

Here is a summary of how it works:

The Promira Quad SPI master employs a flexible sampling scheme on the input data to enable the device to run at higher speeds. The data is internally sampled half a clock cycle later.

Here are some configurations you can apply using API commands:

  • You can configure the SPI timing parameters tSSSCK and tSCKSS by adding the API function ps_queue_spi_delay_cycles between the API functions ps_queue_spi_ss and ps_queue_spi_write.
  • You can configure the SPI timing parameter tWORD by using the API function ps_spi_configure_delays.
  • You can also configure the SPI timing parameter tTXN by adding the API function ps_queue_spi_delay_cycles between submitting twice the function ps_queue_spi_ss  twice: the first one for SS deassert and the second one for SS assert.

For more information, please refer to the AC Characteristics and the API Documentation sections of the Promira Serial Platform I2C/SPI Active User Manual.

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

You can contact sales@totalphase.com for questions about the Promira Serial Platform and other Total Phase products, as well as request a demo that applies to your application.

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