First, read the timer chapter in reference manual.
void usDelay(uint32_t uSec)
{
if(uSec < 2) uSec = 2; // sanitize input value, minimum possible duration using this method is 2usec
usTIM->ARR = uSec - 1; // counter counts up to 0 to ARR inclusive
usTIM->EGR = 1; // generate update, this ensures ARR value is copied to the "active" register even its shadowing is on
usTIM->SR &= ~1; // clear bit 0 i.e. update flag in status register - this is incorrectly written, it should be = rather than &=
usTIM->CR1 |= 1; // start counter
while((usTIM->SR&0x0001) != 1); // wait until update
usTIM->SR &= ~(0x0001); // clear update again, again incorrectly (and here, it's better to stop the counter first)
}
> I wanted to have microsecond delay for my ultrasonic sensor.
There's more to that, e.g. you have to switch on optimization.
JW
