ee201_roller.v

gistfile1.txt

`timescale 1ns / 1ps

module ee201_roller(Clk, Reset, NewX, X);

  /*  INPUTS */
	// Clock & Reset
	input		Clk, Reset;
	input		NewX;

	/**
	TODO: update NUMBINS and WIDTH as needed to change random size

	NUMBINS:
		currently roll 1D20 (20-sided die = 0-19)
	WIDTH:
		to store 19 (NUMBINS-1) requires 5 bit counter
	**/
	localparam
		// NUMBINS 	=  19,
		// WIDTH		=  5;
		// For fair coin
		NUMBINS 	=  1,
		WIDTH		=  1;


	reg [WIDTH-1:0] FastCount;

	/* OUTPUTS */
	output [WIDTH-1:0] X;

	reg  [WIDTH-1:0] X1, X2;
	wire GetWeighted;
	assign X = (GetWeighted) ? X2 : X1;


	assign GetWeighted = 0; // make 1 if weighted; 0 if unweighted

	/** PART II
	// TODO:
	//  1. set X2 values (0 for heads, 1 for tails) for 20/80 unfair coin
	//  2. change GetWeighted = 1
	
	always @ (*)
	 begin : WEIGHTER
  	   case(X1)
  	     4'd0: 		X2 = 0;   // 20%
  	     4'd1: 		X2 = 1;   // 20%
  	     4'd2: 		X2 = 1;   // 20%
  	     4'd3: 		X2 = 1;   // 20%
  	     4'd4: 		X2 = 1;   // 20%
		 default: 	X2 = 1'bX;
	   endcase
	 end
	**/
	 
	always @ (posedge Clk, posedge Reset)
	begin : BIN_COUNTER
		if(Reset)
			begin
				X1 = 0;
				X2 = 0;
			end
		else
		  begin
		    /** FastCount should reset if FastCount reaches NUMBINS-1, else it should increment **/
		    FastCount <= (FastCount == NUMBINS-1) ? 0 : FastCount+1;
  		    if(NewX)
  		    	begin
					/**
					TODO: save X so that the number remains available
					after counter changes next clock
					**/
					// TODONOW - how do I do this?
					X = NewX;
					/* */
  		    	end
		  end
	end

endmodule