Programmable Devices
CPLDs, FPGAs, SoC FPGAs, Configuration, and Transceivers
21604 Discussions

How to clock the module with different frequency?

Altera_Forum
Honored Contributor II
1,125 Views

Hi, 

 

please, advise me what to do. I am working on DE3 with Stratix 3, and want the following module: 

module DATA_Aq(Clk, In, ClkOut, Res); input Clk, ClkOut; input In; output reg Res;  

to be clocked with different speed, for example, with 300, 350, 375, 400MHz. On DE3 board I have external source with 50MHz. 

 

I generated 4 ALTPLL modules that performs 50MHz->300MHHz, 50MHz->350MHz, 50MHz->375MHz, 50MHz->400MHz and trying to do the following: 

module DE3(OSC1_50, SW, InData, ClkOut, CLK_OUT) //... input OSC1_50; // input clock with 50Hz input SW; // depending on SW I wish to clock my project with 300, 350, 375, or 400MHz input InData; input ClkOut; output Res; output CLK_OUT; // this is on board SMA connector where I need my 300-400MHz clock //... wire Clk300, Clk350, Clk375, Clk400; wire Clk; DATA_Aq DATA_Aq_module(Clk, InData, ClkOut, Res); my_pll1 my_pll_module1(OSC1_50, Clk300); my_pll2 my_pll_module2(OSC1_50, Clk350); my_pll3 my_pll_module3(OSC1_50, Clk375); my_pll4 my_pll_module4(OSC1_50, Clk400); // try to switch clocks depending on SW settings assign Clk=(SW)?((SW)?Clk400:Clk375):((SW)?Clk350:Clk300); assign CLK_OUT=(SW)?((SW)?Clk400:Clk375):((SW)?Clk350:Clk300); endmodule  

Additionally I should put the same clock to CLK_OUT pin of this board (it connects over SMA ouput of this board). 

 

Actually my module does not work correctly: I am always getting the same Clk speed on Clk instead of 300,350,375,400MHz. Additionally, I cannot see FMax for Clk, however, I have .sdc file with 

create_clock -name {Clk} -period 2.400 -waveform { 0.000 1.200 }  

 

Please, help me to understand what I did wrong? 

 

Sincerely, 

 

Ilghiz
0 Kudos
0 Replies
Reply