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No PLL output on modelsim

Altera_Forum
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Hi all,  

I am using quartus 2 9.1 sp2. I want to run an ALTPLL considering only one input (Clk) and two output ( c0 and locked output). I have generated the vhdl file for modelsim. I simulate it with 50MHz clock and i see no output on both the output signals. Please see the files below for .bdf and modelsim screenshot. Please help me how to see the output and what changes i need to make.  

 

Thank you 

Ash
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24 Antworten
Altera_Forum
Geehrter Beitragender II
3.858Aufrufe

do you think the input-clock is 50MHz?

Altera_Forum
Geehrter Beitragender II
3.858Aufrufe

Hi Ash, 

 

Just to check with you if the pll_locked got asserted? Can you try to apply a reset to the PLL?
Altera_Forum
Geehrter Beitragender II
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yea that's what i have designed in Mega wizard plug in manager. I have chosen 50MHz for the input clock

Altera_Forum
Geehrter Beitragender II
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Hi akira, 

yea that's what i have designed in Mega wizard plug in manager. I have chosen 50MHz for the input clock 

Thanks
Altera_Forum
Geehrter Beitragender II
3.858Aufrufe

Hi tiny007,  

I added a reset as per what you said. still the output remains the same Undefined. Is there somewhere i am going wrong?
Altera_Forum
Geehrter Beitragender II
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Hi amod, 

 

Two things: you only show 5-6 ns on your waveforms, the PLL models, like real PLLs, take some time to initialize and sync before you get an output. 6ns is not nearly enough time. I forget how long this takes in simulation (I think it's a lot less than for the real devices) but give it a us or so before you give up. Second, it looks like the clock you're feeding it is NOT 50MHz, but 10GHz! The period shown is 0.1ns, check your clock generation. 

 

-Fred
Altera_Forum
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FredH is right. Where is your testbench? Post it here.

Altera_Forum
Geehrter Beitragender II
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Hi FredH i have changed the clock period to 0.02 us and run the simulation for half a second. still my output remains the same. Please see the attachment.  

Thanks  

Ash
Altera_Forum
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Hi krasner,  

 

Could you please explain me how to generate testbench ?
Altera_Forum
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Are you getting any warning when you run modelsim? Perhaps a library is not set up. See this thread: http://www.alteraforum.com/forum/showthread.php?t=21634

Altera_Forum
Geehrter Beitragender II
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A testbench is simply a verilog or vhdl script where you set up you input signals to the system that you are simulating. Usually, you would write one by hand. 

 

How did you set up the input clock signal to your pll system?
Altera_Forum
Geehrter Beitragender II
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yea there is and its Warning: (vsim-3473) Component instance "b2v_inst : altpll0" is not bound.

Altera_Forum
Geehrter Beitragender II
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ok my input clock signal is the input pin clk1 in the bdf file 50MHz. if i look into ppl1.vhd file. i dont have altera_mf header file. Can this be the problem ?

Altera_Forum
Geehrter Beitragender II
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OK this means you are missing the pll library. Make sure you are including all the altera libraries in your modelsim environment.

Altera_Forum
Geehrter Beitragender II
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ok i found out that. Is there a way do that ? Can you direct me here please? I need to get this work.

Altera_Forum
Geehrter Beitragender II
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Yup. you have to include the altera_mf library

Altera_Forum
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It should me under C:/altera/modelsim_ase/altera/<vhdl or verilog>/altera_mf 

 

You have to provide that path
Altera_Forum
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This is a screenshot of the library panel in the modelsim. This contains altera_mf library. But in the vhdl file i dont have altera_mf libary. Please see the screenshots.

Altera_Forum
Geehrter Beitragender II
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posting the attachments again.

Altera_Forum
Geehrter Beitragender II
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In your vhdl file try including LIBRARY altera_mf; 

USE altera_mf.all;
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