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[ NCO ] numerically controlled oscillators

Altera_Forum
Honored Contributor II
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Hi, i have simulated this NCO IP using small ROM options.Then i run the tcl script to simulate the waveform in modelsim.  

 

Now was it possible to display this sin and cos waveform on the oscilloscope? Using the audio out? 

 

The board i am using is altera DE2 board and do please tell me the step on displaying this signal on oscilloscope or vga.
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Altera_Forum
Honored Contributor II
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Connect a DAC to it's output. You can use Video DAC for that I suppose, but I am not sure about audio DAC, since there is audio codec, not simple dac on DE2.

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Altera_Forum
Honored Contributor II
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by video DAC are you referring to Video in port and connect it to oscilloscope?

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Altera_Forum
Honored Contributor II
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No, video out. 

 

As described in DE2 I/O features: 

Video Out (VGA 10-bit DAC)
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Altera_Forum
Honored Contributor II
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Ok so i need to use the vga to pc lcd monitor but i could not find the info in nco manual to send the signal to the monitor. I wish it was easy like assigning the 7-bit segment like i use to do it in verilog.

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Altera_Forum
Honored Contributor II
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No, connect NCO output to one of the DAC colors input and stick oscilloscope probe to that color pin in the VGA connector.

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Altera_Forum
Honored Contributor II
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does assigning the input sine wave to the rgb pin using the pin planner enough for this? or do i need to implement it in the vga_driver.v

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Altera_Forum
Honored Contributor II
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I am not sure, check the datasheet of the DAC. Should be enough, since vga driver needs to generate vertical and horizontal timing impulses, which are not needed in this case.

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