Random Led Blinker on DE10-lite FPGA board: [0-7]LED

[CDolo]

Hi folks,

I have a problem with my random led blinker on fpga.

3-4 leds are turning "on" at the same time.

Although it is random, what I want is that only one led will be "on" at a time.

The code is provided.

-------------------------------------------------------------------

module WhackAMole(

clk,

reset,

LED

);

input wire clk;

input wire reset;

output wire [7:0] LED;

wire [9:0] SYNTHESIZED_WIRE_0;

blinking_leds b2v_inst(

.clk(clk),

.reset(reset),

.rnd(SYNTHESIZED_WIRE_0),

.LED(LED));

randomnumbergenerator b2v_inst1(

.clk(clk),

.reset(reset),

.rnd(SYNTHESIZED_WIRE_0));

endmodule

-------------------------------------------------------------------

module randomnumbergenerator (

input clk,

input reset,

output reg [9:0] rnd

);

wire feedback;

wire [9:0] lfsr_next;

//An LFSR cannot have an all 0 state, thus reset to non-zero value

reg [9:0] reset_value = 13;

reg [9:0] lfsr;

reg [31:0] count;

reg [31:0] counter;

// pragma translate_off

integer f;

initial begin

f = $fopen("output.txt","w");

end

// pragma translate_on

always @ (posedge clk or posedge reset)

begin

if (reset) begin

lfsr <= reset_value;

count <= 32'hF;

rnd <= 0;

end

else begin

lfsr <= lfsr_next;

count <= count + 1;

// a new random value is ready

if (count == 32'd9) begin

count <= 0;

rnd <= lfsr%8; //assign the lfsr number to output after 10 shifts

// pragma translate_off

$fwrite(f,"%0d\n",rnd);

// pragma translate_on

end

end

end

// X10+x7

assign feedback = lfsr[9] ^ lfsr[6];

assign lfsr_next = {lfsr[8:0], feedback};

// pragma translate_off

always @ (*) begin

if (rnd == reset_value) begin

$fclose(f);

$finish();

end

end

// pragma translate_on

endmodule

-------------------------------------------------------------------

module blinking_leds (

input clk, 

input reset,

input [9:0] rnd,

output [7:0] LED);

reg [31:0] counter;

reg [7:0] LED_status;

initial 

begin

counter <= 32'b0;

LED_status <= 0;

end

always @(posedge clk or posedge reset) 

begin

if (reset)

begin

counter <= 32'b0;

LED_status <= 0;

end

else if (counter > 5000000) 

begin

case(rnd)

10'b0000000000: LED_status[0] <= !LED_status[0]; //0

10'b0000000001: LED_status[1] <= !LED_status[1]; //1

10'b0000000010: LED_status[2] <= !LED_status[2]; //2

10'b0000000011: LED_status[3] <= !LED_status[3]; //3

10'b0000000100: LED_status[4] <= !LED_status[4]; //4

10'b0000000101: LED_status[5] <= !LED_status[5]; //5

10'b0000000110: LED_status[6] <= !LED_status[6]; //6

10'b0000000111: LED_status[7] <= !LED_status[7]; //7

endcase

counter <= 32'b0;

end

else 

begin

counter <= counter + 1'b1;

end

end

assign LED = LED_status;

endmodule