[Commit-gnuradio] r7493 - usrp2/trunk/fpga/sdr_lib

[matt]

Author: matt
Date: 2008-01-22 16:06:46 -0700 (Tue, 22 Jan 2008)
New Revision: 7493

Added:
   usrp2/trunk/fpga/sdr_lib/halfband_ideal.v
   usrp2/trunk/fpga/sdr_lib/halfband_tb.v
Log:
testbench courtesy of Brian Padalino


Added: usrp2/trunk/fpga/sdr_lib/halfband_ideal.v
===================================================================
--- usrp2/trunk/fpga/sdr_lib/halfband_ideal.v                           (rev 0)
+++ usrp2/trunk/fpga/sdr_lib/halfband_ideal.v   2008-01-22 23:06:46 UTC (rev 
7493)
@@ -0,0 +1,84 @@
+module halfband_ideal (
+    input                           clock,
+    input                           reset,
+    input                           enable,
+    input                           strobe_in,
+    input   wire    signed  [17:0]  data_in,
+    output  reg                     strobe_out,
+    output  reg     signed  [17:0]  data_out
+) ;
+
+    parameter                       decim   = 1 ;
+    parameter                       rate    = 2 ;
+
+    reg signed              [40:0]  temp ;
+    reg signed              [17:0]  delay[30:0] ;
+    reg signed              [17:0]  coeffs[30:0] ;
+    reg                     [7:0]   count ;
+    integer                         i ;
+
+    initial begin
+        for( i = 0 ; i < 31 ; i = i + 1 ) begin
+            coeffs[i] = 18'd0 ;
+        end
+        coeffs[0]   = -1390 ;
+        coeffs[2]   = 1604 ;
+        coeffs[4]   = -1896 ;
+        coeffs[6]   = 2317 ;
+        coeffs[8]   = -2979 ;
+        coeffs[10]  = 4172 ;
+        coeffs[12]  = -6953 ;
+        coeffs[14]  = 20860 ;
+        coeffs[15]  = 32768 ;
+        coeffs[16]  = 20860 ;
+        coeffs[18]  = -6953 ;
+        coeffs[20]  = 4172 ;
+        coeffs[22]  = -2979 ;
+        coeffs[24]  = 2317 ;
+        coeffs[26]  = -1896 ;
+        coeffs[28]  = 1604 ;
+        coeffs[30]  = -1390 ;
+    end
+
+    always @(posedge clock) begin
+        if( reset ) begin
+            count <= 0 ;
+            for( i = 0 ; i < 31 ; i = i + 1 ) begin
+                delay[i] <= 18'd0 ;
+            end
+            temp        <= 41'd0 ;
+            data_out    <= 18'd0 ;
+            strobe_out  <= 1'b0 ;
+        end else if( enable ) begin
+
+            if( (decim && (count == rate-1)) || !decim ) 
+                strobe_out <= strobe_in ;
+            else
+                strobe_out <= 1'b0 ;
+            
+
+            if( strobe_in ) begin
+                // Increment decimation count
+                count <= count + 1 ;
+
+                // Shift the input
+                for( i = 30 ; i > 0 ; i = i - 1 ) begin
+                    delay[i] = delay[i-1] ;
+                end
+                delay[0] = data_in ;
+
+                // clear the temp reg
+                temp = 18'd0 ;
+                if( (decim && (count == rate-1)) || !decim ) begin
+                    count <= 0 ;
+                    for( i = 0 ; i < 31 ; i = i + 1 ) begin
+                        // Multiply Accumulate
+                        temp = temp + delay[i]*coeffs[i] ;
+                    end
+                    // Assign data output
+                    data_out <= temp >>> 15 ;
+                end
+            end
+        end
+    end
+endmodule

Added: usrp2/trunk/fpga/sdr_lib/halfband_tb.v
===================================================================
--- usrp2/trunk/fpga/sdr_lib/halfband_tb.v                              (rev 0)
+++ usrp2/trunk/fpga/sdr_lib/halfband_tb.v      2008-01-22 23:06:46 UTC (rev 
7493)
@@ -0,0 +1,120 @@
+module halfband_tb( ) ;
+    
+    // Parameters for instantiation
+    parameter               clocks  = 2 ; // Number of clocks per input
+    parameter               decim   = 0 ; // Sets the filter to decimate
+    parameter               rate    = 2 ; // Sets the decimation rate
+
+    reg                     clock ;
+    reg                     reset ;
+    reg                     enable ;
+    reg                     strobe_in ;
+    reg     signed  [17:0]  data_in ;
+    wire                    strobe_out ;
+    wire    signed  [17:0]  data_out ;
+
+    // Setup the clock
+    initial clock = 1'b0 ;
+    always #5 clock <= ~clock ;
+
+    // Come out of reset after a while
+    initial reset = 1'b1 ;
+    initial #100 reset = 1'b0 ;
+
+    // Enable the entire system
+    initial enable = 1'b1 ;
+
+    // Instantiate UUT
+    halfband_ideal 
+      #(
+        .decim      ( decim         ),
+        .rate       ( rate          )
+      ) uut(
+        .clock      ( clock         ),
+        .reset      ( reset         ),
+        .enable     ( enable        ),
+        .strobe_in  ( strobe_in     ),
+        .data_in    ( data_in       ),
+        .strobe_out ( strobe_out    ),
+        .data_out   ( data_out      )
+      ) ;
+    
+    integer i, ri, ro, infile, outfile ;
+
+    // Setup file IO
+    initial begin
+        infile = $fopen("input.dat","r") ;
+        outfile = $fopen("output.dat","r") ;
+        $timeformat(-9, 2, " ns", 10) ;
+    end
+
+    reg                 endofsim ;
+    reg signed  [17:0]  compare ;
+    integer             noe ;
+    initial             noe = 0 ;
+
+    initial begin
+        // Initialize inputs
+        strobe_in <= 1'd0 ;
+        data_in <= 18'd0 ;
+
+        // Wait for reset to go away
+        @(negedge reset) #0 ;
+        
+        // While we're still simulating ...
+        while( !endofsim ) begin
+
+            // Write the input from the file or 0 if EOF...
+            @( posedge clock ) begin
+                #1 ;
+                strobe_in <= 1'b1 ;
+                if( !$feof(infile) )
+                    ri = $fscanf( infile, "%d", data_in ) ;
+                else
+                    data_in <= 18'd0 ;
+            end
+
+            // Clocked in - set the strobe to 0 if the number of
+            // clocks per sample is greater than 1
+            if( clocks > 1 ) begin
+                @(posedge clock) begin
+                    strobe_in <= 1'b0  ;
+                end
+
+                // Wait for the specified number of cycles
+                for( i = 0 ; i < (clocks-2) ; i = i + 1 ) begin
+                    @(posedge clock) #1 ;
+                end
+            end
+        end
+
+        // Print out the number of errors that occured
+        if( noe )
+            $display( "FAILED: %d errors during simulation", noe ) ;
+        else
+            $display( "PASSED: Simulation successful" ) ;
+
+        $stop ;
+    end
+
+    // Output comparison of simulated values versus known good values
+    always @ (posedge clock) begin
+        if( reset )
+            endofsim <= 1'b0 ;
+        else begin
+            if( !$feof(outfile) ) begin
+                if( strobe_out ) begin
+                    ro = $fscanf( outfile, "%d\n", compare ) ;
+                    if( compare != data_out ) begin
+                        $display( "%t: %d != %d", $realtime, data_out, compare 
) ;
+                        noe = noe + 1 ;
+                    end
+                end
+            end else begin
+                // Signal end of simulation when no more outputs
+                endofsim <= 1'b1 ;
+            end
+        end
+    end     
+
+endmodule