QWhy does it take the ADuC834 so long to power on?
ABefore the user code executes, the ADuC834 waits for the crystal to oscillate.
This can take
anywhere from under 1ms to over 300ms. See the ADuC834 datasheet (pg 6, REV A)
for typical figures.
When reset, the ADuC834 must first execute a “power on configuration routine”.
The power on
configuration routine first waits for the crystal to oscillate, and then for
the PLL to lock to its
frequency (about 1ms typically). Once the PLL has gained lock the rest of the
configuration routine which downloads the calibration coefficients to
particular SFRs is executed.
This typically takes about 2ms. When the power on configuration is finished the
start to execute your code starting at address 0.