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// This module is used for creating delays
// reset will reset this module
// fast pulse will go high for one clock cycle 0.2 seconds after a reset
// slow pulse will go high for one clock cycle 0.75 seconds after a reset
// NOTE: Every time this module is reset the time before getting will also
// be reset. So if reset is constantly held high you will never get
// either pulse.
module variable_delay (
input clk,
input reset,
input [4:0] variable_pulse_index,
output variable_pulse
);
reg [31:0] counter = 32'd0;
reg [31:0] variable_pulse_num;
//assign variable_pulse_num = 32'd24000000 - (32'd2000000 * variable_pulse_index);
assign variable_pulse = (counter == variable_pulse_num);
initial begin
counter <= 32'd0;
//variable_pulse_num <= 32'd10;
variable_pulse_num <= 32'd32000000;
end
always @ (negedge clk) begin
if (reset)
counter <= 32'd0;
else
counter <= counter + 32'd1;
end
always @ (posedge clk) begin
case (variable_pulse_index)
5'b00000: variable_pulse_num <= 32'd32000000;
5'b00001: variable_pulse_num <= 32'd31000000;
5'b00010: variable_pulse_num <= 32'd30000000;
5'b00011: variable_pulse_num <= 32'd29000000;
5'b00100: variable_pulse_num <= 32'd28000000;
5'b00101: variable_pulse_num <= 32'd27000000;
5'b00110: variable_pulse_num <= 32'd26000000;
5'b00111: variable_pulse_num <= 32'd25000000;
5'b01000: variable_pulse_num <= 32'd24000000;
5'b01001: variable_pulse_num <= 32'd23000000;
5'b01010: variable_pulse_num <= 32'd22000000;
5'b01011: variable_pulse_num <= 32'd21000000;
5'b01100: variable_pulse_num <= 32'd20000000;
5'b01101: variable_pulse_num <= 32'd19000000;
5'b01110: variable_pulse_num <= 32'd18000000;
5'b01111: variable_pulse_num <= 32'd17000000;
5'b10000: variable_pulse_num <= 32'd16000000;
5'b10001: variable_pulse_num <= 32'd15000000;
5'b10010: variable_pulse_num <= 32'd14000000;
5'b10011: variable_pulse_num <= 32'd13000000;
5'b10100: variable_pulse_num <= 32'd12000000;
5'b10101: variable_pulse_num <= 32'd11000000;
5'b10110: variable_pulse_num <= 32'd10000000;
5'b10111: variable_pulse_num <= 32'd9000000;
5'b11000: variable_pulse_num <= 32'd8000000;
5'b11001: variable_pulse_num <= 32'd7000000;
5'b11010: variable_pulse_num <= 32'd6000000;
5'b11011: variable_pulse_num <= 32'd5000000;
5'b11100: variable_pulse_num <= 32'd4000000;
5'b11101: variable_pulse_num <= 32'd3000000;
5'b11110: variable_pulse_num <= 32'd2000000;
5'b11111: variable_pulse_num <= 32'd1000000;
endcase
// if (reset)
// counter <= 32'd0;
//
// counter <= counter + 32'd1;
end
endmodule
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