AnsweredAssumed Answered

Fast GPIO on Kinetis KF22

Question asked by lous on Apr 8, 2015
Latest reply on Jul 9, 2015 by EARL GOODRICH

Hi,

 

 

I started a new project on the Freedom kinetis KF22 for get the better speed in my application.

 

 

Before I used the atxmega from atmel, but max speed is 32Mhz. So with 120Mhz I think I found the good solution for drive a TFT screen (parallel mode 8bits).

 

 

I set with successful the clock speed and all register but I can't drive GPIO faster than 9Mhz for one period = 110ns to full period, so  . (My core clock is 120Mhz and BusClock is 60Mhz).

 

 

My instruction for driver GPIO is :

 

 

-----------

//Set port to output, mux to gpio, fast slewrate, low drive

 

 

while(1)

{

GPIOD_PTOR = 1<<2; //repeated 100 times in code to avoid the while instructions delay

}

----------

 

 

I see on another topic the same problem but for L series, and the answer is to use the IOPORT register (FGPIO). I can't found this in datasheet/manual. Only in L series.

(https://community.freescale.com/thread/308402)

 

 

Any ideas to my problem ?

 

 

Another question : It's possible to group pin into one byte for write the value in one cycle ? On the KF22 pin is splitted

 

(KDS v2 and SDK 1.1.0)

 

Best regards

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