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Fixing low frequency of the PRS sequence | Cypress Semiconductor

Fixing low frequency of the PRS sequence

Summary: 8 Replies, Latest post by Bob Marlowe on 21 May 2012 05:24 AM PDT
Verified Answers: 3
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user_208641989's picture
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8 posts

Hello Cypress Community

I am trying to use the PRS component in PSoC Creator. One of the requirements that I have is to fix the frequency of the PRS betweeen 100KHz to 200KHz. Essentially the Bandwidth should be 100 kHz, with fixed lower and higher frequency. How can I do this in PSoC ?

Virtually,

Sherlock

user_1377889's picture
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10803 posts

Due to the definition of "random" it will be difficult to fullfill your requirements. The maximum frequency you can get will be the clock-frequency divided by two (when the output changes at two adjacent pulses). but there is no theoretical limit for the lowest frequency. 

 

Bob 

user_208641989's picture
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8 posts

I love google !! The lowest frequency is going to be clock /Resolution and the highest logic frequency (not switching harmonics) is clock/2.  \m/

user_1377889's picture
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10803 posts

Yes, as I said Clock divided by two, but your low frequency of 100kHz will not be easy to reach, even with a resolution of 2 bits and a clock of 400kHz.

 

Bob

user_208641989's picture
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8 posts

or an input clock of 400kHz, maximum frequency from the PRS = 400kHz/2 = 200kHz.

And minimum frequency for resolution repeat cycle time 4 is 400kHz/4 = 100kHz. Correct ?

user_1377889's picture
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10803 posts

Yes, that is what I wanted to say. Since you may specify a resolution of 4, you'll get 15 different values (repeated) .

 

Bob

PS: I have been to Bakerstreet 221b

user_208641989's picture
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8 posts

Ha, I see. How did I miss you.

user_208641989's picture
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8 posts

Bob, could you provide me a much more discrete answer. What should I do to contain my frequencis between two known frequencies from a PRS component.

I can buy you a beer, if you could help me with this.

user_1377889's picture
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10803 posts

Well, as I red your last posts and with what I know about PRS I would...

to make a long story short, see attached project and have some measures.

 

Bob

Any beer is taken/given only personally.

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