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Diffstat (limited to 'common/rtl')
-rw-r--r-- | common/rtl/novena_regs.v | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/common/rtl/novena_regs.v b/common/rtl/novena_regs.v new file mode 100644 index 0000000..716f650 --- /dev/null +++ b/common/rtl/novena_regs.v @@ -0,0 +1,132 @@ +//====================================================================== +// +// novena_regs.v +// ------------- +// Global registers for the Cryptech Novena FPGA framework. +// +// +// Author: Pavel Shatov +// Copyright (c) 2015, 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. +// +//====================================================================== + +`timescale 1ns / 1ps + +module board_regs + ( + input wire clk, + input wire rst, + + input wire cs, + input wire we, + + input wire [ 7 : 0] address, + input wire [31 : 0] write_data, + output wire [31 : 0] read_data + ); + + + //---------------------------------------------------------------- + // Internal constant and parameter definitions. + //---------------------------------------------------------------- + // API addresses. + localparam ADDR_CORE_NAME0 = 8'h00; + localparam ADDR_CORE_NAME1 = 8'h01; + localparam ADDR_CORE_VERSION = 8'h02; + localparam ADDR_DUMMY_REG = 8'hFF; // general-purpose register + + // Core ID constants. + localparam CORE_NAME0 = 32'h50565431; // "PVT1" + localparam CORE_NAME1 = 32'h20202020; // " " + localparam CORE_VERSION = 32'h302e3130; // "0.10" + + //---------------------------------------------------------------- + // Registers. + //---------------------------------------------------------------- + reg [31: 0] tmp_read_data; + + // dummy register to check that you can actually write something + reg [31: 0] reg_dummy; + + //---------------------------------------------------------------- + // Wires. + //---------------------------------------------------------------- + wire [31 : 0] core_name0 = CORE_NAME0; + wire [31 : 0] core_name1 = CORE_NAME1; + wire [31 : 0] core_version = CORE_VERSION; + + //---------------------------------------------------------------- + // Concurrent connectivity for ports etc. + //---------------------------------------------------------------- + assign read_data = tmp_read_data; + + //---------------------------------------------------------------- + // storage registers for mapping memory to core interface + //---------------------------------------------------------------- + always @ (posedge clk or posedge rst) + begin + if (rst) + begin + reg_dummy <= {32{1'b0}}; + end + else if (cs && we) + begin + // write operations + case (address) + ADDR_DUMMY_REG: + reg_dummy <= write_data; + endcase + end + end + + always @* + begin + tmp_read_data = 32'h00000000; + + if (cs && !we) + begin + // read operations + case (address) + ADDR_CORE_NAME0: + tmp_read_data = core_name0; + ADDR_CORE_NAME1: + tmp_read_data = core_name1; + ADDR_CORE_VERSION: + tmp_read_data = core_version; + ADDR_DUMMY_REG: + tmp_read_data = reg_dummy; + endcase + end + end + +endmodule + +//====================================================================== +// EOF novena_regs.v +//====================================================================== |