TMS320F28384S: SPI's maximum transfer rate when not using high-speed pins

Wesley C

What is the SPI's maximum transfer rate when not using high-speed pins?

I see on the data sheet that the max speed is 50MHz for SPI high speed, but what is the max when the GPIO used for the SPI are not high-speed capable?

Thanks,

-Wes

over 3 years ago

0 Wesley C over 3 years ago

Intellectual 925 points

For example, a 200MHz system clock with a LSPCLK prescalar set to /1 would allow for a 50MHz transfer rate for the SPI, but if the SPI GPIO are not set to high-speed GPIO pins, what would be the maximum transfer rate be?

0 Gus Martinez over 3 years ago in reply to Wesley C

TI__Mastermind 30541 points

This depends on the setup and hold timings and how they match the device you are connecting to. For example, you can see that in normal master mode the F2838x device requires 20ns setup time. If you run the SPICLK at 50MHz, that's a whole cycle! A more realistic case would be SPICLK = 25MHz, where half a cycle is 20ns, but this still depends on the output timing of the device driving SPISOMI.

0 Wesley C over 3 years ago in reply to Gus Martinez

Intellectual 925 points

Thanks Gus. I appreciate it.

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TMS320F28384S: SPI's maximum transfer rate when not using high-speed pins