Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

False triggering on dff?

I am using a Cyclone III starter kit with Quartus II v8.1 web edition. I am using library components to make a "one shot" with variable delay times in the msec range. There does not appear to be an...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

1) Yes. That's the same as jakobjones suggested with registering the comparator output.

2) It's in the library, because it's just another configuration variant of the lpm_counter MegaFunction. I meant to use the carry output. However, thinking about my suggestion, I realized, that carry is basically a combinational output, that can have glitches too. So you should better use the registered variant. You may need to adjust the compare value, because the DFF output is delayed by one clock.