[Commit-gnuradio] r6905 - gnuradio/branches/developers/matt/u2f/models

[matt]

Author: matt
Date: 2007-11-14 16:10:24 -0700 (Wed, 14 Nov 2007)
New Revision: 6905

Modified:
   gnuradio/branches/developers/matt/u2f/models/uart_rx.v
Log:
corrected model of a receiver


Modified: gnuradio/branches/developers/matt/u2f/models/uart_rx.v
===================================================================
--- gnuradio/branches/developers/matt/u2f/models/uart_rx.v      2007-11-14 
23:02:05 UTC (rev 6904)
+++ gnuradio/branches/developers/matt/u2f/models/uart_rx.v      2007-11-14 
23:10:24 UTC (rev 6905)
@@ -4,7 +4,7 @@
 //   Only does 8N1, requires the baud clock
 
 module uart_rx (input baudclk, input rxd);
-   reg [10:0] sr = 11'b0;
+   reg [8:0] sr = 9'b0;
    reg [3:0]  baud_ctr = 4'b0;
    wire       byteclk = baud_ctr[3];
 
@@ -19,22 +19,22 @@
        baud_ctr <= baud_ctr + 1;
 
    always @(posedge byteclk)
-     sr <= { sr[9:0], rxd };
+     sr <= { rxd, sr[8:1] };
 
    reg [3:0]  state = 0;
    always @(posedge byteclk)
      case(state)
        0 : 
-        if(sr[1] & ~sr[0])  // found start bit
+        if(~sr[8] & sr[7])  // found start bit
           state  <= 1;
        1, 2, 3, 4, 5, 6, 7, 8 :
         state <= state + 1;
        9 : 
         begin
            state <= 0;
-           if(sr[0])
+           $write("%c",sr[7:0]);
+           if(~sr[8])
              $display("Error, no stop bit\n");
-           $write("%c",sr[8:1]);
         end
        default :
         state <= 0;