Subversion Repositories nlprg

`include "../rtl/nlprg7.v"
 
module prng7_tb ();
 
parameter N = 7;
 
reg ck;
reg rst;
 
 
wire [N-1:0] o ;
 
 
nlprg7 nlprg7_u (
  .ck(ck),
  .rst(rst),
  .o(o)
);
 
// dump variables
 
initial begin 
 
        $dumpfile( "./wave/prng7_tb.vcd");
        $dumpvars( 0, prng7_tb );
 
end
 
 
integer f = -1 ; // file handler
 
// generate clocks and reset
 
initial begin
 
        f = $fopen("./log/prng7_tb.log","w+");
 
        rst = 1'b1     ;
        #5 rst = ~ rst ;
		#5 rst = ~ rst ;
		#5 rst = ~ rst ;
        ck  = 1'b1     ;
forever #5 ck  = ~ ck  ;
 
end
 
// generate counter
 
reg [N-1:0] cnt;
 
always@ ( posedge ck or posedge rst ) begin : cnt_process
 
  if ( rst ) cnt <= {N{1'b0}}  ;
  else       cnt <= cnt + 1'b1 ;
 
end
 
// delay reset
 
reg rst_d0;
reg rst_d1;
 
always@ ( posedge ck or posedge rst ) begin : reset_delay_process
 
  if ( rst ) begin
 
    rst_d0 <= 1'b1   ;
    rst_d1 <= 1'b1   ;
 
  end else begin
 
    rst_d0 <= 1'b0   ;
    rst_d1 <= rst_d0 ;
 
  end
 
end
 
// generate endsim
 
reg endsim;
reg pass;
 
wire prng_start_state = ( o   == {N{1'b0}});
wire cnt_start_state  = ( cnt == {N{1'b0}});
 
 
always@ ( posedge ck or posedge rst ) begin : lock_process
 
  if      ( rst                                                   ) begin
    endsim <= 1'b0 ;
    pass   <= 1'b0 ;
  end else if ( prng_start_state & ( ! rst_d1 )                   ) begin
    endsim <= 1'b1 ;
    pass   <= 1'b0 ;
  end else if ( cnt_start_state  & prng_start_state & ( ! rst_d1 ) ) begin
    endsim <= 1'b1 ;
    pass   <= 1'b1 ;
  end else if ( cnt_start_state  & ( ! rst_d1 )                   ) begin
    endsim <= 1'b1 ;
    pass   <= 1'b0 ;
  end
 
end
 
 
// display and finish
 
always@ ( posedge ck or posedge rst ) begin : display_process
 
  if          (( ! endsim ) && ( ! rst ))  begin
    $fdisplay(f,"%10d %10b", cnt , o) ;
  end else if ( endsim                  )  begin
    $fclose(f);
    $finish ;
  end
 
end
 
endmodule