Time delay when operating with DAC in STM32L4

[GMate.2]

Hi everyone!

I use 8 MHz external oscillator for my MCU. For TIM1 there is no prescaler in CUBE, so I expect this timer to tick with pure 8MHz frequency. And therefore I expect to see 0.125 us * 2 * 2 = 0.5 us period of signal. But actually I have 24 us period duration. What does slow down my DAC output? How can I achieve 0.5 us period for my pulse signal?

Thanks.

[waclawek.jan · Accepted solution]

fast_delay() alone takes a couple of instrucions = couple of cycles to call, and then return from it.

But, more importantly Cube/HAL functions are bloated, so HAL_DAC_SetValue may easily execute hundreds of instructions until it gets to write the value to DAC register and return.

JW

[GMate.2]

Thank you for the explanation

[AScha.3]

try simple test : comment / leave away the fast_delay(); lines.

then you see the speed/delay of the HAL_Dac-set.. timing .