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Altera_Forum
Honored Contributor
11 years agoCyclone V PLL outclock is zero
Hi everyone I use PLL to generate 137Mhz for my Qsys system. The inclock is 125MHz which is from on-board oscillator, but the outclock of PLL is zero, and I don't know why. :( I build my projec...
Altera_Forum
Honored Contributor
11 years agoThe locked signal should go high if pll is locked to the reference clock and you are safe to use it.
If it stays low, there is obiously something wrong. Check the reset signal of that pll. Typically it is high active! I also would advice you to connect the locked- and reset-signal together with the clock to some pin header and analyse it with an oscilloscope.