//TRAFFIC LIGHT
CONTROLLER
module
tlc(N,E,W,S,clk);
output
[2:0] N,E,W,S;
input
clk;
parameter
s0=3'b000;
parameter
s1=3'b001;
parameter
s2=3'b010;
parameter
s3=3'b011;
parameter
s4=3'b100;
parameter
s5=3'b101;
parameter
s6=3'b110;
parameter
s7=3'b111;
parameter
R=3'b001;
parameter
Y=3'b010;
parameter
G=3'b100;
reg
[2:0] N,E,W,S;
reg
[2:0] state;
integer
t=0;
initial //initialize
begin
state <= s0;
t <= 0;
end
//--------------TIMING
CONTROL-----------
always@(posedge
clk)
begin
// next_state=state;
case(state)
s0:if(t==20) //N=G
begin
state=s1;
t=0;
end
else
t=t+1;
s1:if(t==5) //N=Y
begin
state=s2;
t=0;
end
else
t=t+1;
s2:if(t==20) //E=G
begin
state=s3;
t=0;
end
else
t=t+1;
s3:if(t==5) //E=Y
begin
state=s4;
t=0;
end
else
t=t+1;
s4:if(t==20) //S=G
begin
state=s5;
t=0;
end
else
t=t+1;
s5:if(t==5) //S=Y
begin
state=s6;
t=0;
end
else
t=t+1;
s6:if(t==20) //W=G
begin
state=s7;
t=0;
end
else
t=t+1;
s7:if(t==5) //W=Y
begin
state=s0;
t=0;
end
else
t=t+1;
default: state=s0;
endcase
end
//end of always block
//--------------LIGHT
CONTROL-----------
always @ (state)
begin
case
(state)
s0:{N,E,W,S}={G,R,R,R};
s1:{N,E,W,S}={Y,R,R,R};
s2:{N,E,W,S}={R,G,R,R};
s3:{N,E,W,S}={R,Y,R,R};
s4:{N,E,W,S}={R,R,G,R};
s5:{N,E,W,S}={R,R,Y,R};
s6:{N,E,W,S}={R,R,R,G};
s7:{N,E,W,S}={R,R,R,Y};
default:{N,E,W,S}={G,R,R,R};
endcase
end
endmodule
