AnsweredAssumed Answered

Fast GPIO on Kinetis KF22

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




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





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.




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