Configuring the GPIO takes too long?

RE: Configuring the GPIO takes too long?

Turbo J — Wed, 11 Mar 2026 07:22:10 GMT

Yes, your data is real.

I had to look it up, turns out GPIO is an AHB peripherial on the NRF52840. On later chips (53xx, 54xxx) its an ABP peripherial that can run on a slower clock.

You can try to interleave your NRF_P2 and NRF_P1 writes - that might use the write buffers more efficient. But the GPIO register access is indeed much slower on the newer chips.

RE: Configuring the GPIO takes too long?

abstract1340 — Wed, 11 Mar 2026 02:15:23 GMT

Hi Turbo J, It's not a measurement issue. Executing KEY_IO_CFG_INPUT() 1000 times in a loop takes more than 8 ms, so the function KEY_IO_CFG_INPUT() itself consumes a lot of time, not because gpio_pin_configure_dt is inaccurate.

Moreover, even when changed to OUTSET and OUTCLR, the measured time is still long

RE: Configuring the GPIO takes too long?

Turbo J — Tue, 10 Mar 2026 09:47:38 GMT

Looking at the implementation, gpio_pin_configure_dt() might take a non-trivial amount of your measured time here. Also depends on assert and tracing configs.

For these kind of measurements you want to use the OUTSET and OUTCLR registers directly.