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/*******************************************************************************

 *

 * Copyright 2012, Sinclair R.F., Inc.

 *

 * Test bench for examples/i2c_tmp100

 *

 ******************************************************************************/

`timescale 1ns/1ps

module tb;

// 97 MHz clock

reg s_clk = 1'b1;

always @ (s_clk) s_clk <= #5.155 ~s_clk;

reg s_rst = 1'b1;

initial begin

  repeat (5) @ (posedge s_clk);

  s_rst <= 1'b0;

end

tri1 s_SCL;

tri1 s_SDA;

wire s_UART_Tx;

i2c_tmp100 it_inst(

  // synchronous reset and processor clock

  .i_rst        (s_rst),

  .i_clk        (s_clk),

  // I2C ports

  .io_scl       (s_SCL),

  .io_sda       (s_SDA),

  // UART_Tx ports

  .o_UART_Tx    (s_UART_Tx)

);

integer ix_i2c;

reg [0:26] i2c_out = 27'b111111110_101010101_010100001;

reg s_sensor_sda = 1'b1;

initial begin

  @ (negedge s_SDA);

  if (s_SCL == 1'b0) begin

    $display("%13d : Malformed I2C start signal");

    $finish;

  end

  ix_i2c = 0;

  repeat (27) begin

    @ (negedge s_SCL);

    #700;

    s_sensor_sda = i2c_out[ix_i2c];

    ix_i2c = ix_i2c + 1;

  end

  s_sensor_sda = 1'b1;

end

assign s_SDA = (s_sensor_sda) ? 1'bz : 1'b0;

localparam baud = 9600;

localparam dt_baud = 1.0e9/baud;

reg [8:0] deser = 9'h1FF;

initial forever begin

  @ (negedge s_UART_Tx);

  #(dt_baud/2.0);

  repeat (9) begin

    #dt_baud;

    deser = { s_UART_Tx, deser[1+:8] };

  end

  if (deser[8] != 1'b1)

    $display("%13d : Malformed UART transmition, $time");

  else if ((8'h20 <= deser[0+:8]) && (deser[0+:8]<=8'h80))

    $display("%13d : Sent 0x%02H : %c", $time, deser[0+:8], deser[0+:8]);

  else

    $display("%13d : Sent 0x%02H", $time, deser[0+:8]);

end

// Progress meter

initial forever begin #100_000_000; $display("%13d : progress report", $time); end

// terminate after 10 msec (use 2.1e9 for 2.1 sec)

initial begin

  while ($realtime < 1.0e7) @ (posedge s_clk);

  $finish;

end

initial begin

  $dumpfile("tb.lxt");

  $dumpvars();

end

endmodule