//
// $Id: $
//
//  primesys.v : test wrapper and BVCI ssram xtor for the primes.vnl test.
module SIMSYS();


  reg reset;
  reg clk;

  parameter dwidth = 32;

  wire [31:0] primes_count;
  reg [31:0] primes_vol;
  reg [dwidth-1:0] PA_rdata;
  reg PA_rerror;
  reg PA_reop;
  wire PA_rspack;
  reg PA_rspval;
  wire [dwidth/8-1:0] PA_le;
  wire [31:0] PA_addr;
  wire [dwidth-1:0] PA_wdata;
  wire PA_eop;
  wire [1:0] PA_cmd;
  wire [6:0] PA_plen;
  reg PA_cmdack;
  wire PA_cmdval;

  reg [31:0] Array [0:10000];

   primes iprimes(reset, clk, primes_count, primes_vol, PA_rdata, PA_rerror, PA_reop, PA_rspack, PA_rspval, PA_le, PA_addr, PA_wdata, PA_eop, PA_cmd, PA_plen, PA_cmdval, PA_cmdack);

  initial clk =0;
  initial begin reset = 1; # 1000 reset = 0; end
  always #100 clk = !clk;

  reg busy; // At most one command in process at a time.
  reg [7:0] inctr, outctr;
  reg [31:0] answers [0:255];

  always @(posedge clk) if (reset)
	 begin inctr <= 0;
		busy <= 0;
		outctr <= 0;
	  	PA_cmdack <= 0;
		end
  	 else begin
  	 PA_cmdack <= !busy;

	 if (PA_cmdval && PA_cmdack && PA_eop) busy <= 1;

	 if (PA_cmdval && PA_cmdack && PA_cmd == 2) // write command
	    begin
		 Array[PA_addr] <= PA_wdata;
		 $display("ssram write [%d] := %d", PA_addr, PA_wdata);
		 inctr <= inctr + dwidth/8;
		 outctr <= 0;
		 end

	 if (PA_cmdval && PA_cmdack && PA_cmd == 1) // read command
	    begin
		 $display("ssram read [%d] -> %d", PA_addr, Array[PA_addr]);
		 answers[inctr] = Array[PA_addr];
		 inctr <= inctr + dwidth/8;
		 outctr <= 0;
		 end

	 // Response process
	 if (busy) begin
	 	 PA_rspval <= 1;
		 PA_rdata = answers[outctr];
		 outctr <= (outctr+dwidth/8 == inctr) ? 0: outctr+dwidth/8;
		 if (outctr+dwidth/8 == inctr) begin 
			PA_reop <= 1; inctr <= 0; busy <= 0;
			end
		end
	 else begin PA_rspval <= 0; PA_reop <= 0; end


	 //if (PA_cmdval) $display("Cmd %d, len=%d, count=%d/%d, addr=%d", PA_cmd, PA_plen, inctr, outctr, PA_addr);

	 $display("Monitor primes_count=%d", primes_count);

	 end


  initial #100000000 begin $display("Finish, primes_count=%d", primes_count); $finish(); end


endmodule

// eof