[time-nuts] DDS - Cosine v. Sine LUT
cupido at mail.ua.pt
Tue Jun 21 19:18:19 UTC 2011
A quarter table cos is exactly the same as a quarter table sin.
Only backwards, and not telling which quarter it is makes it a
quarter of either sin or cos. For one single output becomes irrelevant
as you only need one.
So I think it is just a matter of taste the name to call it.
On 6/21/2011 8:03 PM, KD0GLS wrote:
>> On Jun 21, 2011, at 13:39, Chris Albertson wrote:
>> I used only 90 degrees of the table.
> Yes, as did I and most implementations, but why a cosine quarter-table instead of the more common sine? A quick look at the data sheets (and the waveforms in the theory-of-op sections) for the two devices suggests they are clearly calling out one or the other, but without rationale regarding the choice.
> Brent, KD0GLS, Minneapolis
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
More information about the time-nuts