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LPSPI clock freq and frequency of operation

Question asked by Vlad Damian on Jun 29, 2017
Latest reply on Jul 6, 2017 by Daniel Martynek

Hello,

I am currently trying to figure out details about LPSPI and I am looking into the datasheet, but somehow I am still in doubt.

Also, because I am new on embedded world.

1.)What is the difference between peripheral LPSPI frequency (which is 56MHz in HSRUN mode) and frequency of operation (which is 24 MHz or 14 MHz, depending of which voltage you have)?

 

 2.)The main point is that I am trying to test the faster speed that SPI can run. 

I have tested the example code (LPSPI) and modified the sourceClock and baudRate, but all I could get was 4 MHz.

I also read in another post that for faster freq, you need to run it into DMA mode (now I am running in LPSPI_USING_INTERRUPTS mode) . I am trying to configure the DMA now, maybe I can go up with the freq.

But I would like to know why is this limitation of 4 MHz on USING_INTERRUPTS mode and also, can I go up to 24 MHz clock freq?

Thank you ! 

PS: hope that my question is not too confusing or misleading. 

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