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Altera_Forum's avatar
Altera_Forum
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15 years ago

24bit counter by 400 MHz

Hi all, i am working with Cyclone III Starter Kit, the max frequency is 400 MHz. I would like to use this high frequency to achieve a 2.5ns resolution. with the megafunction i can easy make the ...
Altera_Forum's avatar
Altera_Forum
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15 years ago

Depending on your exact application, you might also use two counters at 200MHz, one with inverted clock, the other without. Then you can add the values of both counters. (You should ensure that the tsu/th from the pin to the counters is about the same for both counters. If the enable-input is directly a device-pin, you should add some synchronizer-stages, regardless if you use one or two counters.)

If you combine this method with the cascaded counter someone mentioned, you can achieve even higher resolutions if required.

Regards,

Thomas