Change SPI Speed in Code

[barrypurtymun]

Hello NXP,

I am using Kinetis Design Studio with a K60 chip.  I have a touch screen that needs to be initialized via SPI at 10 MHz or less.  The touch screen can communicate at 30 MHz after initialization. I have a bus clock speed of 60 MHz and need to change my SPI prescaler divider from 6 to 2 (10 MHz to 30 MHz) after I run my initialization code.  I used processor expert (SyncroMaster) to configure my SPI port.  Please advise how I should change my SPI bus speed after the touch screen has been initialized. 

Thank you. 

[kerryzhou]

Hi Barry Purtymun,

   After you initialized the SPI for the touch screen initialization, and want to use the higher spi baud, you can try to modify the SPI baudrate prescaler register directly.

  It is SPIx_CTARn[PBR], please use the register control directly on your code at first, just the test the function, whether it meet your demand.

If you still have question about it, please kindly let me know!

Have a great day,
Kerry

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