module pwm4_basic (
input clk ,
input rst ,
input [3:0] duty ,
output reg pwm_out
);
reg [3:0]count;
always @(posedge clk) begin
if(rst) begin
count <= 4'd0 ;
pwm_out <= 1'b0 ;
end
else begin
count <= count + 1'b1 ;
if(count < duty)
pwm_out <= 1'b1 ;
else
pwm_out <= 1'b0;
end
end
endmodule