gaganlock.v

Verilog code for Digital lock

module digilock(clk,i,unlock,mode,pass,invalid,reset,iled);

input [9:0] i;
//input [3:0] s;
input mode,clk,reset;

output unlock,pass,invalid;
output [9:0] iled;
//wire [3:0] t;

reg [3:0] c,ledc,s,p1,p2,p3,p4,s1,s2,s3,s4,mp1,mp2,mp3,mp4;
reg [9:0] ca,iled;
reg pass,manclk,unlock,mode1,invalid,reset1;
reg [25:0] ctr;

reg count;
initial begin
	c<=0;
//        in<=4'b0000;
	pass<=0;
	manclk<=0;
	ledc<=4'b0000;
	p1<=0;p2<=1;p3<=2;p4<=3;
	s1<=0;s2<=0;s3<=0;s4<=0;
	mp1<=p1;mp2<=p2;mp3<=p3;mp4<=p4;
//	a<=0;b<=0;c<=0;d<=0;e<=0;f<=0;g<=0;h<=0;
	count<=0;
	invalid<=0;
	reset1<=0;mode1<=0;unlock<=0;
end

always @(posedge clk) begin 
	ctr<=ctr+1;
	
	if(ctr==20000000)begin
		manclk<=~manclk;
		pass<=manclk;
		ctr<=0;
				
	end
	if(manclk) begin
		ca<=i;
		mode1<=mode;
		reset1<=reset;
		if(ca[0]) begin
			ledc<=4'b0000;
			count<=count+1;
		iled[0]<=1;
		end
		else if(ca[1]) begin
			ledc<=4'b0001;
			count<=count+1;
		iled[1]<=1;
		end	
			
		else if(ca[2]) begin
			ledc<=4'b0010;
			count<=count+1;
		iled[2]<=1;
		end	
			
		else if(ca[3]) begin
			ledc<=4'b0011;
			count<=count+1;
			iled[3]<=1;
		end	
			
		else if(ca[4]) begin
			ledc<=4'b0100;
			count<=count+1;
			iled[4]<=1;
		end	
			
		else if(ca[5]) begin
			ledc<=4'b0101;
			count<=count+1;
		iled[5]<=1;
		end	
			
		else if(ca[6]) begin
			ledc<=4'b0110;
			count<=count+1;
		iled[6]<=1;
		end	
			
		else if(ca[7]) begin
			ledc<=4'b0111;
			count<=count+1;
		iled[7]<=1;
		end	
			
		else if(ca[8]) begin
			ledc<=4'b1000;
			count<=count+1;
		iled[8]<=1;
		end					
			
		else if(ca[9]) begin
			ledc<=4'b1001;
			count<=count+1;
	iled[9]<=1;
		end
//		s<=ledc;
		
		if(count==1)begin
			s1<=ledc;
			ledc<=0;
		end
			else if(count==2)begin
				s2<=ledc;ledc<=0;
			end
				else if(count==3)begin
					s3<=ledc;ledc<=0;
				end
					else if(count==4)begin
						s4<=ledc;ledc<=0;
					end
		
//compare
		if(s1==p1 && s2==p2 && s3==p3 && s4==p4 && count<=4 && mode1==0)begin
			unlock<=1;
			count<=0;
			s1<=0;s2<=0;s3<=0;s4<=0;
		end
		
//password change
		if(unlock & mode1)begin
			if(s1==p1 && s2==p2 && s3==p3 && s4==p4 && count<=4)begin
				s1<=0;s2<=0;s3<=0;s4<=0;
				count<=0;invalid<=0;
			end
			else begin
				invalid<=1;
			end
			if(~invalid & mode1)begin
				p1<=s1;p2<=s2;p3<=s3;p4<=s4;
				s1<=0;s2<=0;s3<=0;s4<=0;mode1<=0;reset1<=0;
			end	
		end
		if(reset1==1)begin
		   unlock<=0;
		iled<=0;
			p1<=mp1;p2<=mp2;p3<=mp3;p4<=mp4;
			mode1<=0;
		end
	end
end					
endmodule