void delayMicroseconds(uint32_t microsec)
Performs a delay for the duration specified by microsec
.
Time measurement is done using the TickTimer count. When a long delay is specified, the CPU clock is reduced during polling.
Within the setup()
and wakeup()
functions, since the TickTimer is not yet running, delays are implemented using a while-loop. In this case, the discrepancy from the specified value may be significant. The loop counter is calibrated for 32 MHz. If the CPU clock is altered within these functions, errors proportional to the clock change will occur.
If a short duration such as 10 microseconds or less is specified as a parameter, the error may be relatively large.