clock divider with counter

how about posting some code.

Btw, using logic clocks is not recommened. You should use clock enables isntead.

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how about posting some code.

Btw, using logic clocks is not recommened. You should use clock enables isntead.

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Here goes the code :

module clock_divide(clk_out,clk_50);

input clk_50;

output clk_out;

reg[24:0] count; // to count 25 million you need 25 bit counter

reg clk_out;

parameter TC=25'd25000000-25'd1;

initial begin

count=0;

clk_out=0;

end

always @(posedge clk_50)

begin

if (count==0)begin

count <=TC;

clk_out <=~clk_out;

end

else

count<=count-1'b1;

end

endmodule

module up_counter( out, enable , clk, reset );

output [7:0] out;

input enable, reset, clk;

reg [7:0] out;

//-------------Code Starts Here-------

always @(posedge clk)

if (reset) begin

out <= 8'h0 ;

end else if (enable) begin

out <= out + 1;

end

endmodule

// hex to seven segment decoder

module hexadecimalcounter(hex_1, hex_0, hex_num);

input [3:0] hex_num;

output[6:0] hex_1;

output[6:0] hex_0;

reg [6:0] hex_1;

reg [6:0] hex_0;

always @(hex_num)

begin

case (hex_num)

4'h0: {hex_1, hex_0} = {7'b1111111, 7'b1000000}; // 7-seg for 0

4'h1: {hex_1, hex_0} = {7'b1111111, 7'b1111001} ; // 7-seg for 1

4'h2: {hex_1, hex_0} = {7'b1111111, 7'b0100100} ; // 7-seg for 2

4'h3: {hex_1, hex_0} = {7'b1111111, 7'b0110000} ; // 7-seg for 3

4'h4: {hex_1, hex_0} = {7'b1111111, 7'b0011001} ; // 7-seg for 4

4'h5: {hex_1, hex_0} = {7'b1111111, 7'b0010010} ; // 7-seg for 5

4'h6: {hex_1, hex_0} = {7'b1111111, 7'b0000010} ; // 7-seg for 6

4'h7: {hex_1, hex_0} = {7'b1111111, 7'b1111000} ; // 7-seg for 7

4'h8: {hex_1, hex_0} = {7'b1111111, 7'b0000000} ; // 7-seg for 8

4'h9: {hex_1, hex_0} = {7'b1111111, 7'b0011000} ; // 7-seg for 9

4'ha: {hex_1, hex_0} = {7'b1111001, 7'b1000000} ; // 7-seg for A

4'hb: {hex_1, hex_0} = {7'b1111001, 7'b1111001} ; // 7-seg for B

4'hc: {hex_1, hex_0} = {7'b1111001, 7'b0100100} ; // 7-seg for C

4'hd: {hex_1, hex_0} = {7'b1111001, 7'b0110000} ; // 7-seg for D

4'he: {hex_1, hex_0} = {7'b1111001, 7'b0011001} ; // 7-seg for E

4'hf: {hex_1, hex_0} = {7'b1111001, 7'b0010010} ; // 7-seg for F

default: {hex_1, hex_0} = {7'b1111001, 7'b1111111} ; // 7-segment code for blank

endcase

end

endmodule

// top level module counter_hexa

module counter_hexa( enable, clk_50, reset, hex_1, hex_0, clk_out);

input enable, clk_50, reset;

output [7:0] hex_1, hex_0;

output wire clk_out;

wire [7:0] out;

clock_divide ch_cd(clk_out,clk_50);

up_counter ch_upc(clk_out, reset, enable, out);

hexadecimalcounter ch_hxdc(out, hex_1, hex_0);

endmodule

Here is the code. Hope to hear from you soon.

how about using a PLL to divide the clock? but i am not sure whether this range of 1MHz is allowed or not.

You may check with PLL

In your top level module, it looks to me like where you instantiate the module "up_counter", you have listed the ports in the wrong order. Same for the "hexadecimalcounter" instantiation.

You are using the "ordered list" method of module instantiation. At the cost of some extra typing, you could instead use the "connect by name" method and be less likely to have problems of this sort.

I think you may have some additional issues with your instantiation of "hexadecimalcounter". I am not clear on just what you are trying to achieve but the sizes of the signals you are connecting to the module are not the same as defined by the module. It also looks like your counter will count from 0 to 255 but the display will only go from 0 to 15.

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In your top level module, it looks to me like where you instantiate the module "up_counter", you have listed the ports in the wrong order. Same for the "hexadecimalcounter" instantiation.

You are using the "ordered list" method of module instantiation. At the cost of some extra typing, you could instead use the "connect by name" method and be less likely to have problems of this sort.

I think you may have some additional issues with your instantiation of "hexadecimalcounter". I am not clear on just what you are trying to achieve but the sizes of the signals you are connecting to the module are not the same as defined by the module. It also looks like your counter will count from 0 to 255 but the display will only go from 0 to 15.

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I am trying to achieve a hexadecimal counter which will count from 00 to FF. any additional comments or points to join in my code. What could be done to make it run ?

This involves a bit of speculation on my part since I don't know the details of your display but it looks like your module "hexadecimalcounter" is meant to take one 4-bit (=1 hex digit) and then display it in decimal format using two seven-segment display characters. What you want is a module that takes one 4-bit value and displays it in hex format using one seven segment display character. You can use one of those modules for the upper 4 bits of your counter and another for the lower 4 bits. Right now you are trying to put an 8 bit value into the module. Take a careful look at your hexadecimalcounter module, it looks like a functional module but not for what I think you want to do.

So you have logical errors, size mismatches, and parameter ordering errors. You need to do a thorough review of the code.

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This involves a bit of speculation on my part since I don't know the details of your display but it looks like your module "hexadecimalcounter" is meant to take one 4-bit (=1 hex digit) and then display it in decimal format using two seven-segment display characters. What you want is a module that takes one 4-bit value and displays it in hex format using one seven segment display character. You can use one of those modules for the upper 4 bits of your counter and another for the lower 4 bits. Right now you are trying to put an 8 bit value into the module. Take a careful look at your hexadecimalcounter module, it looks like a functional module but not for what I think you want to do.

So you have logical errors, size mismatches, and parameter ordering errors. You need to do a thorough review of the code.

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Yeah I changed my value to 8 bit already, still i see the same problem output is constant. Do you see any mistakes in my hexadecimal counter ?

I will be re-posting my code with slight corrections.

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After you have addressed the comments raised by mvanpelt (primarily the port connections being incorrect), try posting your code again and a description of how it is broken / what you have fixed since the previous post.

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I am trying to make a counter which will count from 00 to FF and will display it in seven segment on my board.

I am re-posting code. I have done bit of re-ordering as mvanpelt said. Still i see the same output. I should see my seven segment counting but the output shown at my display is 80 and when I simulate the code, i just see 00 and 40. I am trying to this from past 2 weeks and I think I am stuck forever.

Here is the code:

module clock_divide(clk_out,clk_50);

input clk_50;

output clk_out;

reg[24:0] count; // to count 25 million you need 25 bit counter

reg clk_out;

parameter TC=25'd25000000-25'd1;

initial begin

count=0;

clk_out=0;

end

always @(posedge clk_50)

begin

if (count==0)begin

count <=TC;

clk_out <=~clk_out;

end

else

count<=count-1'b1;

end

endmodule

module up_counter(clk, enable, reset, out );

output [7:0] out;

input enable, reset, clk;

reg [7:0] out;

//-------------Code Starts Here-------

always @(posedge clk)

if (reset) begin

out <= 8'h0 ;

end else if (enable) begin

out <= out + 1;

end

endmodule

// hex to seven segment decoder

module hexadecimalcounter(hex_1, hex_0, hex_num);

input [3:0] hex_num;

output[6:0] hex_1;

output[6:0] hex_0;

reg [6:0] hex_1;

reg [6:0] hex_0;

always @(hex_num)

begin

case (hex_num)

8'h0: {hex_1, hex_0} = {7'b1111111, 7'b1000000}; // 7-seg for 0

8'h1: {hex_1, hex_0} = {7'b1111111, 7'b1111001} ; // 7-seg for 1

8'h2: {hex_1, hex_0} = {7'b1111111, 7'b0100100} ; // 7-seg for 2

8'h3: {hex_1, hex_0} = {7'b1111111, 7'b0110000} ; // 7-seg for 3

8'h4: {hex_1, hex_0} = {7'b1111111, 7'b0011001} ; // 7-seg for 4

8'h5: {hex_1, hex_0} = {7'b1111111, 7'b0010010} ; // 7-seg for 5

8'h6: {hex_1, hex_0} = {7'b1111111, 7'b0000010} ; // 7-seg for 6

8'h7: {hex_1, hex_0} = {7'b1111111, 7'b1111000} ; // 7-seg for 7

8'h8: {hex_1, hex_0} = {7'b1111111, 7'b0000000} ; // 7-seg for 8

8'h9: {hex_1, hex_0} = {7'b1111111, 7'b0011000} ; // 7-seg for 9

8'ha: {hex_1, hex_0} = {7'b1111001, 7'b1000000} ; // 7-seg for A

8'hb: {hex_1, hex_0} = {7'b1111001, 7'b1111001} ; // 7-seg for B

8'hc: {hex_1, hex_0} = {7'b1111001, 7'b0100100} ; // 7-seg for C

8'hd: {hex_1, hex_0} = {7'b1111001, 7'b0110000} ; // 7-seg for D

8'he: {hex_1, hex_0} = {7'b1111001, 7'b0011001} ; // 7-seg for E

8'hf: {hex_1, hex_0} = {7'b1111001, 7'b0010010} ; // 7-seg for F

endcase

end

endmodule

// top level module counter_hexa

module counter_hexa( clk_50, enable, reset, hex_1, hex_0);

input enable, clk_50, reset;

output [7:0] hex_1, hex_0;

wire clk_out;

wire [7:0] out;

clock_divide cd(clk_50, clk_out);

up_counter upc(clk_out, reset, enable, out);

hexadecimalcounter hxdc(out, hex_0, hex_1);

endmodule

The port connections are still incorrect. You should follow mvanpelt's suggestion and use named ports during the instantiation. By being more explicit, it will show you some of your mistakes.

e.g.

This:

up_counter ch_upc
(
  .clk         ( clk_out ),
  .enable      ( enable  ),
  .reset       ( reset   ),
  .out         ( out     )
);

vs.

module up_counter(clk, enable, reset, out );
...
endmodule;
up_counter ch_upc(clk_out, reset, enable, out);