- Run the simulation by clicking the Run All button .
Observe the sine signal output in the waveform. The Wave window can be unlocked from Main window layout to view it as standalone.
- Click the Float button in the title bar of the Waveform Configuration window.
- Click the Zoom Fit button to display the whole time spectrum in the Waveform Configuration window.
Notice that the low frequency sine output is incorrect. You can view the waveform in detail by zooming into the Waveform window. When you zoom into the waveform, you can use the horizontal and vertical scroll bars to pan down the full waveform.
As seen in the figure above, when the value of sineSel is 0, which indicates a low
frequency sine selection, the analog
sine[19:0] output is not a
proper sine wave, indicating a problem in the design or the testbench.