Horst Dieter wrote:
> CD= MCKI / (16 * Baud Rate) = 10* 10^6 Hz / (16 * 192Baud) = 8,13 => 8
> CD= MCKI / (16 * Baud Rate) = (10* 10^6 Hz / 8) / (16 * 192Baud) = 1,017
> => 1
From that and the diagram I have to agree with you rather than your
professor, however there are some ambiguities:
Where does the divide by eight the second example come from? It is not
indicated in the illustration you posted. Which one of those are you
actually using?
You said the CPU is clocked at 10MHz, but the example indicates an MCKI
of 100MHz. Is 10MHz rather he crystal frequency and 10 the clock
multiplier? 10MHz is rather low for an ARM part.
Note that the USART is a vendor defined peripheral component and not a
standard ARM core component, it would be useful if you could specify the
part so we could simply take a look at the data sheet or user manual and
get a definitive answer. (or you could do that).
Horst Dieter wrote:
> and what is meant by 192baud is this the same as 19200 Baud? if not how
> does it differ?
It seems we are both confused by that. As I said refer to the data sheet
for the part, or let us know what the part is. If Baud merely refers to
the units (as in Hz earlier in the equation), 192 is a rather odd and
very low rate (and does not match the answer given), shouldn't that be
"19200 Baud" I wonder? It still does not make much sense however.
Don't assume that your prof is correct, it would not be the first time
inaccurate information was provided (especially if this is the forst
presentation of the material). That said be diplomatic and discrete is
pointing out any error - your marks may depend upon it! ;-)
Clifford
