gpio rising/falling time

[Jim]

Hello!

I need sensitive gpio.

I want that is gpio rising in 20[nsec].

However, the test results using the function below show that the gpio rise time is 200 nsec.

nrf_gpio_pin_toggle(17); / nrf_gpio_pin_clear(17); / nrf_gpio_pin_set(17);

How can I raise it in 20 [nsec]?

That is possible?

Do you have any code to reference?

Thank you for always resolving your question.

[Jørn]

Hello Jim

If you look at page 155 of the nRF52832 product specification you will see the rise and fall times that have been simulated for the nRF52832.

Firstly you can see from this that the times are significantly reduced by enabling high drive for the pins. To enable high drive for a pin when using the GPIO drivers you can call nrf_gpio_cfg() with the correct arguments, where the drive argument is set to NRF_GPIO_PIN_H0H1. Otherwise you can write directly to the hardware peripheral registers. This will provide high drive for both high and low state.

Secondly the rise and fall times are dependent on the capacitance present at the pin, so be sure to limit the capacitance of the load you have connected to the pin.

Best regards

Jørn Frøysa

[Jim]

I solved this problem by applying it to a real board. It took 200 [nsec] on the development board(PCA10040), but I confirmed that it was below 20 [nsec] on my making PCB board.

The second way you gave me was the right way.

Thank you, Jørn!