How to configure DCM in Virtex-5 as a Time-toDigital Converter (TDC)

[msdarvishi]

Hello everybody,

I am working on DCM in Virtex-5 (XC5VLX50T) to configure it as a Time-toDigital Converter (TDC) and measure the minimum posible resolution that can be measured in TDC using DCM, but I do not know how to start this procedure? Can anyone give me a hint or an example?

Thanks,

 

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The DCM is a Digital Clock Management block it's not a TDC. It behaves like a PLL and locks to an incoming reference clock.

If you are planning on using the DCM as your clock source for a TDC that is a different case, In that case you will probably want to generate the highest frequency clock that still meets timing as the clock source for the lower order bit prescaler, then use a much slower enabled counter for the upper bits. You will have to multicycle the binary counter. In this way you might manage to run the whole thing in a V5 at whatever is the maximum output frequency a DCM can generate.

Take a look at this wiki page on TDC

 

[msdarvishi]

The DCM is a Digital Clock Management block it's not a TDC. It behaves like a PLL and locks to an incoming reference clock.

If you are planning on using the DCM as your clock source for a TDC that is a different case, In that case you will probably want to generate the highest frequency clock that still meets timing as the clock source for the lower order bit prescaler, then use a much slower enabled counter for the upper bits. You will have to multicycle the binary counter. In this way you might manage to run the whole thing in a V5 at whatever is the maximum output frequency a DCM can generate.

Take a look at this wiki page on TDC

Hello,
Thank you for your reply. I know the principles of TDC and DCM. I plan to uses DCM and its delay line to force it to act like a TDC, if possible. I want to figure out and measure the DCM's limitations by measurement. Do you have any idea about it?

Thanks,