Honored Contributor
Honored ContributorALTINT_OSC is a newly introduced Megafunction. Previously, no option to connect the internal oscillator to FPGA logic fabric had been provided by Quartus. Apparently Altera didn't yet finish the documentation linked in MegaWizard, so the link goes to a different document.
There's also no clear specification about oscillator frequency range. It has been mentioned as "80 MHz internal chip oscillator" related to CRC generation. My guess is that there's actually only one oscillator, divided down for different purposes. If it has the same PVT variation as the DCLK configuration oscillator, we can assume a 40 to 80 MHz range, typically 60 MHz. A tighter frequency range would require some kind of individual calibration and non-volatile parameter storage. P.S.: Two supplements: - The internal oscillator has been previously available in wysiwyg.cycloneiii_components - I measure a frequency of 57.69 MHz, which supports my above frequency range assumption
