Library for common Verilog modules.

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diff --git a/memory/bram_1wo_1ro_readfirst.v b/memory/bram_1wo_1ro_readfirst.v
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+//======================================================================
+//
+// Copyright (c) 2015, 2018 NORDUnet A/S All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+// - Redistributions of source code must retain the above copyright
+//   notice, this list of conditions and the following disclaimer.
+//
+// - Redistributions in binary form must reproduce the above copyright
+//   notice, this list of conditions and the following disclaimer in the
+//   documentation and/or other materials provided with the distribution.
+//
+// - Neither the name of the NORDUnet nor the names of its contributors may
+//   be used to endorse or promote products derived from this software
+//   without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+//======================================================================
+
+module bram_1wo_1ro_readfirst #
+(
+    parameter MEM_WIDTH     = 32,
+    parameter MEM_ADDR_BITS =  8
+)
+(
+    input   clk,
+
+    input  [MEM_ADDR_BITS-1:0] a_addr,
+    input                      a_wr,
+    input  [MEM_WIDTH    -1:0] a_in,
+    output [MEM_WIDTH    -1:0] a_out,
+
+    input  [MEM_ADDR_BITS-1:0] b_addr,
+    output [MEM_WIDTH    -1:0] b_out
+);
+
+
+    //
+    // BRAM
+    //
+    (* RAM_STYLE="BLOCK" *)
+    reg [MEM_WIDTH-1:0] bram[0:(2**MEM_ADDR_BITS)-1];
+
+
+    //
+    // Initialization for Simulation
+    //
+    /*
+    integer c;
+    initial begin
+        for (c=0; c<(2**MEM_ADDR_BITS); c=c+1)
+        bram[c] = {MEM_WIDTH{1'b0}};
+    end
+    */
+
+
+
+    //
+    // Output Registers
+    //
+    reg [MEM_WIDTH-1:0] bram_reg_b;
+
+    assign a_out = 32'hDEADCE11;
+    assign b_out = bram_reg_b;
+
+    
+    //
+    // Note, that when both ports are accessing the same location, conflict can
+    // potentionally arise. See Xilinx UG473 (pages 19-20, "Conflict
+    // Avoidance") for more information. In our configuration to avoid that the
+    // write port must be coded to operate in READ_FIRST mode. If the write
+    // port is overwriting the same address the read port is accessing, the 
+    // write port must read the previously stored data (not the data it is
+    // writing, as that would be WRITE_FIRST mode).
+    //
+
+
+    //
+    // Write-Only Port A
+    //
+    always @(posedge clk)
+        //
+        if (a_wr) bram[a_addr] <= a_in;
+
+
+    //
+    // Read-Only Port B
+    //
+    always @(posedge clk)
+        //
+        bram_reg_b <= bram[b_addr];
+
+
+endmodule