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help on dds programing AD9830

i have read ad9830 dds ic datasheet, but i have steel problem how i>
should program it, for example i want to use pararel port for
interfacing , and for example want 3.1MHZ on out put, how i should
use D0 to D15 and A0,A1,A2? should i use both freq reg ( 0,1) and
all 4 phase reg ? or one is enouth? according to datasheet 3.1mhz
word is FDF3B64 , how ity calculated, if you could expain how to
calculate interfacing word?
any help would be most appreciated
thanks
payam
 
R

Rene Tschaggelar

Jan 1, 1970
0
i have read ad9830 dds ic datasheet, but i have steel problem how i>
should program it, for example i want to use pararel port for
interfacing , and for example want 3.1MHZ on out put, how i should
use D0 to D15 and A0,A1,A2? should i use both freq reg ( 0,1) and
all 4 phase reg ? or one is enouth? according to datasheet 3.1mhz
word is FDF3B64 , how ity calculated, if you could expain how to
calculate interfacing word?

payam79bb,
You appear not to read the replies. Nevertheless :

Starting with an external clock of 1MHz and a frequency control
word of 1, it takes 2^32 clocks for 2*pi phase.
This means the output frequency is 1MHz/2^32 = 0.232mHz (milliHertz)
For a frequency control word of 4295 you therefore get
4295 * 1MHz / 2^32 =1.000008Hz

and so on.

Rene
 
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