We use Max 10 device and internal oscillator is used.
When dragging internal oscillator clock to wave in Altera Modelsim , the clock is always high impedance.
Please let us know how to make it happen.
For clock output signal, you need to enable the internal oscillator. Input(oscena) high to enable the oscillator.
Refer the "Table 1. Frequency Range for Supported Intel Devices"
Find the screenshot for 55 MHz.