How to measure RING OSCILLATOR frequency?

[Sumathigokul]

I want to measure the frequency of ring oscillator circuit i inserted in my design. i made circuit schematic using xilinx ISE. During behavioral simulation, my circuit is switching its output, but i could not see its waveform. Hence i could not measure its delay i.e. frequency.
When i select the mode of simulation as post-route, it shows my design is not yet instantiated (question mark near design), when i try to instantiate, its not doing so. Finally i could not measure ring oscillator frequency.

Please let me know how to measure, ring oscillator frequency......

 

[mrflibble]

Braindead stupid and easy method (and thus awesomely reliable, because it does not presuppose brain settings):
- implement in real hardware
- export signal to outside of fpga
- view signal with your favorite scope
- analyze signal with your favorite frequency counter

The ButButButILoveMySimulator method:
- plonk SAVE attributes on things & stuff so the synthesizer does not optimize away your ring osc
- do a post place & route simulation to get fairly reliable delay simulation