nRF52 wirting GPIOS direct with immediate effect

[prpaul]

Hi I have ported a simple function from nRF51 to nRF52 which Outputs PWM coded Startup Diagnose Information via a GPIO. The Timing is generated by wait Loops and GPIO will be toggled by direct writing to OUTSET Register. I have noticed that the Timing is no longer precise on the nRF52. It seems, that writing to the OUTSET Register not always takes effect immediately. I guess it is an effect caused by the System bus write buffer.

Qustions: What is the correct way to force a GPIO to react immediately? I have tried the following to toggle the GPIO which seems to work:

• read OUTSET Register
• write OUTSET Register
• read OUTSET Register

Where can i get more Information about the System bus write buffer?

Thank you for help. Kind regards Paul

[prpaul]

Hi I have solved the problem by implementing the function using a Timer, PPI channels and GPIOTE as you have proposed. Thank you very much. Paul