RE: Execution time on nrf52840

kirkus — Tue, 12 Mar 2019 16:25:25 GMT

The cycle counter works really well for short measurements:

uint32_t start;
uint32_t stop;
uint32_t elapsed;

// enable DWT
CoreDebug->DEMCR |= 0x01000000;

// Reset cycle counter
DWT->CYCCNT = 0;

// enable cycle counter
DWT->CTRL |= 0x1;

start = DWT->CYCCNT;
nrf_delay_ms(1000);
stop = DWT->CYCCNT;
elapsed = stop-start;
NRF_LOG_INFO("cycles for nrf_delay_ms(1000) = %u", elapsed);
// <info> app: cycles for nrf_delay_ms(1000) = 64018002

RE: Execution time on nrf52840

Jared — Mon, 11 Mar 2019 13:08:17 GMT

Hi,

The Application timer use the LFCLK, try using the Timer peripheral instead. It uses the HFCLK.

Best regards

Jared