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Altera_Forum
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15 years ago

cpld needs a external Oscillator ?

i use cpld as combinational logic.the circuits don't need Oscillator.so if i don't connect a external Oscillator to cpld,can it work normally? moreover,can internal oscillator be used as general...
Altera_Forum's avatar
Altera_Forum
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15 years ago

As long as you do not use registers like a DFF, you do not need any clock.

But be aware that using pure combinatorial logic output could mean that there are glitches or spikes due to different combinatorial delays.

I assume you talk about the MaxII device, then have a look at

page 42 (http://www.altera.com/literature/hb/max2/max2_mii5v1.pdf)

it should be possible to use the internal oscilator.