verilog compiler error: near ";": syntax error, unexpected ';' -

i'm trying write traffic light fsm code green, yellow, red has delay of 20 time units. goes green-yellow-red-yellow- green. code , i'm getting error while using 'repeat' delay.

errors:

error: c:/users/desktop/design/tlights.v(33): near ";": syntax error, unexpected ';'
error: c:/users/desktop/design/tlights.v(37): near ";": syntax error, unexpected ';'
error: c:/users/desktop/design/tlights.v(44): near ";": syntax error, unexpected ';'

`define delay 20;  module tlights(clk, rst, y);   input clk, rst;  output [1:0]y;  reg [1:0]y;  reg [1:0] cs,ns;  integer p;   parameter red = 2'd2;  parameter orange = 2'd1;  parameter green = 2'd0;   parameter s0 = 2'd0;  parameter s1 = 2'd1;  parameter s2 = 2'd2;    always@(posedge clk or negedge rst)  begin  if(!rst)  begin   cs<=s0;  end  else   cs<=ns;  end   always@(cs)  begin  case(cs)         s0: begin               repeat (`delay) @(posedge clk); // <-- error here                 ns=s1;              end         s1: begin              repeat (`delay) @(posedge clk); // <-- error here              if (p==0)                   ns =s2;                 else                   ns=s0;             end         s2:    begin                repeat (`delay) @(posedge clk); // <-- error here                  ns<=s1;                end         default: ns<=s0;       endcase    end     always@ (cs)   begin     case(cs)       s0:begin            y<=2'b00;            p<=0;          end       s1:y<=2'b01;        s2:begin           y<=2'b10;           p<=1;          end            endcase  end  endmodule 

the problem `define statement. `define similar #define in c/c++. statements literal substitution , terminator end of line, not semi-colon. repeat (`delay) means repeat ( 20; ). remove ; , simulate.

even with correction not synthesize. blocking statements (i.e. @,#, , wait) not allowed inside combinational logic. synthesizable, you'll need add flip-flops counter. next state , next counter combinational logic should following:

always @* begin   // default value   ns = cs;   next_counter  = counter + 1;   // update value   case(cs)     s0: begin       if (counter >= `delay) begin         ns = s1;         next_counter = 0;       end     end    /* ... */   endcase end 

also, remember assign flops non-blocking (<=). blocking (=) assigning combinational logic.