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-rw-r--r--src/rtl/test_core.v221
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+//======================================================================
+//
+// test_core.v
+// -----------
+// A simple test core used during verification of the coretest test
+// module. The test core provies a few read and write registers
+// that can be tested. Additionally it also provides an 8-bit data
+// port directly connected to one of the internal registers.
+//
+//
+// Author: Joachim Strombergson
+// Copyright (c) 2014 SUNET
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or
+// without modification, are permitted provided that the following
+// conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//
+// 2. 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.
+//
+// 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 OWNER 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 test_core(
+ input wire clk,
+ input wire reset_n,
+
+ input wire cs,
+ input wire we,
+ input wire [7 : 0] address,
+ input wire [31 : 0] write_data,
+ output wire [31 : 0] read_data,
+ output wire error,
+
+ output wire [7 : 0] debug
+ );
+
+
+ //----------------------------------------------------------------
+ // Internal constant and parameter definitions.
+ //----------------------------------------------------------------
+ // Programming interface
+ parameter ADDR_CORE_ID_0 = 8'h00;
+ parameter ADDR_CORE_ID_1 = 8'h01;
+ parameter ADDR_CORE_TYPE_0 = 8'h02;
+ parameter ADDR_CORE_TYPE_1 = 8'h03;
+ parameter ADDR_RW_REG = 8'h10;
+ parameter ADDR_DEBUG_REG = 8'h20;
+
+ parameter CORE_ID_0 = 32'h74657374; // "test"
+ parameter CORE_ID_1 = 32'h636f7265; // "core"
+ parameter CORE_TYPE_0 = 32'h30303030; // "00000"
+ parameter CORE_TYPE_1 = 32'h30303162; // "001b"
+
+ parameter RW_DEFAULT = 32'h11223344;
+ parameter DEBUG_DEFAULT = 8'h55;
+
+
+ //----------------------------------------------------------------
+ // Registers including update variables and write enable.
+ //----------------------------------------------------------------
+ reg [31 : 0] rw_reg;
+ reg [31 : 0] rw_new;
+ reg rw_we;
+
+ reg [7 : 0] debug_reg;
+ reg [7 : 0] debug_new;
+ reg debug_we;
+
+
+
+ //----------------------------------------------------------------
+ // Wires.
+ //----------------------------------------------------------------
+ reg tmp_error;
+ reg [31 : 0] tmp_read_data;
+
+
+ //----------------------------------------------------------------
+ // Concurrent connectivity for ports etc.
+ //----------------------------------------------------------------
+ assign error = tmp_error;
+ assign read_data = tmp_read_data;
+ assign debug = debug_reg;
+
+
+ //----------------------------------------------------------------
+ // reg_update
+ // Update functionality for all registers in the core.
+ // All registers are positive edge triggered with synchronous
+ // active low reset. All registers have write enable.
+ //----------------------------------------------------------------
+ always @ (posedge clk)
+ begin: reg_update
+ if (!reset_n)
+ begin
+ rw_reg <= RW_DEFAULT;
+ debug_reg <= DEBUG_DEFAULT;
+ end
+ else
+ begin
+ if (rw_we)
+ begin
+ rw_reg <= rw_new;
+ end
+
+ if (debug_we)
+ begin
+ debug_reg <= debug_new;
+ end
+ end
+ end // reg_update
+
+
+ //---------------------------------------------------------------
+ // read_write_logic
+ //
+ // Read and write register logic.
+ //---------------------------------------------------------------
+ always @*
+ begin: read_write_logic
+ // Defafult assignments
+ rw_new = 32'h00000000;
+ rw_we = 0;
+ debug_new = 8'h00;
+ debug_we = 0;
+ tmp_read_data = 32'h00000000;
+ tmp_error = 0;
+
+ if (cs)
+ begin
+ if (we)
+ begin
+ // Write operations.
+ case (address)
+ ADDR_RW_REG:
+ begin
+ rw_new = write_data;
+ rw_we = 1;
+ end
+
+ ADDR_DEBUG_REG:
+ begin
+ debug_new = write_data[7 : 0];
+ debug_we = 1;
+ end
+
+ default:
+ begin
+ tmp_error = 1;
+ end
+ endcase // case (address)
+ end
+
+ else
+ begin
+ // Read operations.
+ case (address)
+ ADDR_CORE_ID_0:
+ begin
+ tmp_read_data = CORE_ID_0;
+ end
+
+ ADDR_CORE_ID_1:
+ begin
+ tmp_read_data = CORE_ID_1;
+ end
+
+ ADDR_CORE_TYPE_0:
+ begin
+ tmp_read_data = CORE_TYPE_0;
+ end
+
+ ADDR_CORE_TYPE_1:
+ begin
+ tmp_read_data = CORE_TYPE_1;
+ end
+
+ ADDR_RW_REG:
+ begin
+ tmp_read_data = rw_reg;
+ end
+
+ ADDR_DEBUG_REG:
+ begin
+ tmp_read_data = {24'h000000, debug_reg};
+ end
+
+ default:
+ begin
+ tmp_error = 1;
+ end
+ endcase // case (address)
+ end
+
+ end
+ end // read_write_logic
+
+endmodule // test_core
+
+//======================================================================
+// EOF test_core.v
+//======================================================================