Subversion Repositories openmsp430

/*===========================================================================*/

/*                                 DIGITAL I/O                               */

/*---------------------------------------------------------------------------*/

/* Test the Digital I/O interface.                                           */

/*===========================================================================*/

`define VERY_LONG_TIMEOUT

// Data rate

parameter UART_FREQ   = 115200;

integer   UART_PERIOD = 1000000000/UART_FREQ;

reg [7:0] rxbuf;

integer   rxcnt;

task uart_rx;

      begin

         @(negedge UART_TXD);

         rxbuf = 0;

         #(UART_PERIOD*3/2);

         for (rxcnt = 0; rxcnt < 8; rxcnt = rxcnt + 1)

           begin

              rxbuf = {UART_TXD, rxbuf[7:1]};

              #(UART_PERIOD);

           end

         $write("%s", rxbuf);

         $fflush();

      end

endtask

task uart_tx;

      input [7:0] txbuf;

      reg [9:0] txbuf_full;

      integer   txcnt;

      begin

         UART_RXD = 1'b1;

         txbuf_full = {1'b1, txbuf, 1'b0};

         #(UART_PERIOD);

         for (txcnt = 0; txcnt < 10; txcnt = txcnt + 1)

           begin

              UART_RXD   =  txbuf_full[txcnt];

              #(UART_PERIOD);

           end

      end

endtask

initial forever uart_rx;

initial

   begin

      $display(" ===============================================");

      $display("|                 START SIMULATION              |");

      $display(" ===============================================");

      repeat(5) @(posedge CLK_50MHz);

      stimulus_done = 0;

      UART_RXD = 1'b1;

      // Select hardware uart

      SW1 = 1'b1;

      SW0 = 1'b0;

      // Wait for welcome message to be received

      repeat(120000) @(posedge mclk);

      // Send something

      uart_tx("B");

      uart_tx("o");

      uart_tx("n");

      uart_tx("j");

      uart_tx("o");

      uart_tx("u");

      uart_tx("r");

      uart_tx(" ");

      uart_tx(":");

      uart_tx("-");

      uart_tx(")");

      uart_tx("\n");

      repeat(10000) @(posedge mclk);

      stimulus_done = 1;

      repeat(10) @(posedge mclk);

      $display("\n");

      $finish();

   end