How to write code of seven segment display using Nios ii in eclipse?

Hi,

There is no certain example of displaying a seven segment display with NIOS but it is a very simple example.

You can create an RTL code to get the value from NIOS and then translate it to 7 segment display. The NIOS can send the seven segment value to the following circuit and the value will be displayed as seven segment.

always @*
begin
      case(seven_seg_val)
            4'b0000: LED_out = 7'b0000001; // "0"  
            4'b0001: LED_out = 7'b1001111; // "1" 
            4'b0010: LED_out = 7'b0010010; // "2" 
            4'b0011: LED_out = 7'b0000110; // "3" 
            4'b0100: LED_out = 7'b1001100; // "4" 
            4'b0101: LED_out = 7'b0100100; // "5" 
            4'b0110: LED_out = 7'b0100000; // "6" 
            4'b0111: LED_out = 7'b0001111; // "7" 
            4'b1000: LED_out = 7'b0000000; // "8"  
            4'b1001: LED_out = 7'b0000100; // "9" 
            default: LED_out = 7'b0000001; // "0"
      endcase
 
end

another option is to this into the C/C++ code by using switch case for example to translate the value to 7-seg

There are many examples online you can find like the following: