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Diffstat (limited to 'rtl/modexpa7_buffer_user.v')
| -rw-r--r-- | rtl/modexpa7_buffer_user.v | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/rtl/modexpa7_buffer_user.v b/rtl/modexpa7_buffer_user.v new file mode 100644 index 0000000..abb772b --- /dev/null +++ b/rtl/modexpa7_buffer_user.v @@ -0,0 +1,197 @@ +//====================================================================== +// +// Copyright (c) 2016, 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 modexpa7_buffer_user + #(parameter OPERAND_ADDR_WIDTH = 5) // 1024 / 32 = 32 -> 5 bits + ( + input wire clk, + + input wire bus_cs, + input wire bus_we, + input wire [ADDR_WIDTH_TOTAL-1:0] bus_addr, + input wire [31:0] bus_data_wr, + output wire [31:0] bus_data_rd, + + input wire [OPERAND_ADDR_WIDTH-1:0] ro_modulus_bram_addr, + output wire [31:0] ro_modulus_bram_out, + + input wire [OPERAND_ADDR_WIDTH-1:0] ro_message_bram_addr, + output wire [31:0] ro_message_bram_out, + + input wire [OPERAND_ADDR_WIDTH-1:0] ro_exponent_bram_addr, + output wire [31:0] ro_exponent_bram_out, + + input wire [OPERAND_ADDR_WIDTH-1:0] rw_result_bram_addr, + input wire rw_result_bram_wr, + input wire [31:0] rw_result_bram_in + ); + + + // + // Locals + // + localparam ADDR_WIDTH_TOTAL = OPERAND_ADDR_WIDTH + 2; + + localparam [1: 0] BUS_ADDR_BANK_MODULUS = 2'b00; + localparam [1: 0] BUS_ADDR_BANK_MESSAGE = 2'b01; + localparam [1: 0] BUS_ADDR_BANK_EXPONENT = 2'b10; + localparam [1: 0] BUS_ADDR_BANK_RESULT = 2'b11; + + // + // Address Decoder + // + wire [OPERAND_ADDR_WIDTH-1:0] bus_addr_operand_word = bus_addr[OPERAND_ADDR_WIDTH-1:0]; + wire [ 1:0] bus_addr_operand_bank = bus_addr[ADDR_WIDTH_TOTAL-1:ADDR_WIDTH_TOTAL-2]; + + + // + // Modulus Memory + // + wire [31: 0] bus_data_rd_modulus; + + ram_1rw_1ro_readfirst # + ( + .MEM_WIDTH (32), + .MEM_ADDR_BITS (OPERAND_ADDR_WIDTH) + ) + mem_modulus + ( + .clk (clk), + + .a_addr (bus_addr_operand_word), + .a_wr (bus_cs & bus_we & (bus_addr_operand_bank == BUS_ADDR_BANK_MODULUS)), + .a_in (bus_data_wr), + .a_out (bus_data_rd_modulus), + + .b_addr (ro_modulus_bram_addr), + .b_out (ro_modulus_bram_out) + ); + + + // + // Message Memory + // + wire [31: 0] bus_data_rd_message; + + ram_1rw_1ro_readfirst # + ( + .MEM_WIDTH (32), + .MEM_ADDR_BITS (OPERAND_ADDR_WIDTH) + ) + mem_message + ( + .clk (clk), + + .a_addr (bus_addr_operand_word), + .a_wr (bus_cs & bus_we & (bus_addr_operand_bank == BUS_ADDR_BANK_MESSAGE)), + .a_in (bus_data_wr), + .a_out (bus_data_rd_message), + + .b_addr (ro_message_bram_addr), + .b_out (ro_message_bram_out) + ); + + + // + // Exponent Memory + // + wire [31: 0] bus_data_rd_exponent; + + ram_1rw_1ro_readfirst # + ( + .MEM_WIDTH (32), + .MEM_ADDR_BITS (OPERAND_ADDR_WIDTH) + ) + mem_exponent + ( + .clk (clk), + + .a_addr (bus_addr_operand_word), + .a_wr (bus_cs & bus_we & (bus_addr_operand_bank == BUS_ADDR_BANK_EXPONENT)), + .a_in (bus_data_wr), + .a_out (bus_data_rd_exponent), + + .b_addr (ro_exponent_bram_addr), + .b_out (ro_exponent_bram_out) + ); + + + // + // Result Memory + // + wire [31: 0] bus_data_rd_result; + + ram_1rw_1ro_readfirst # + ( + .MEM_WIDTH (32), + .MEM_ADDR_BITS (OPERAND_ADDR_WIDTH) + ) + mem_result + ( + .clk (clk), + + .a_addr (rw_result_bram_addr), + .a_wr (rw_result_bram_wr), + .a_in (rw_result_bram_in), + .a_out (), + + .b_addr (bus_addr_operand_word), + .b_out (bus_data_rd_result) + ); + + + // + // Output Selector + // + reg [1: 0] bus_addr_operand_bank_prev; + always @(posedge clk) bus_addr_operand_bank_prev = bus_addr_operand_bank; + + reg [31: 0] bus_data_rd_mux; + assign bus_data_rd = bus_data_rd_mux; + + always @(*) + // + case (bus_addr_operand_bank_prev) + // + BUS_ADDR_BANK_MODULUS: bus_data_rd_mux = bus_data_rd_modulus; + BUS_ADDR_BANK_MESSAGE: bus_data_rd_mux = bus_data_rd_message; + BUS_ADDR_BANK_EXPONENT: bus_data_rd_mux = bus_data_rd_exponent; + BUS_ADDR_BANK_RESULT: bus_data_rd_mux = bus_data_rd_result; + // + default: bus_data_rd_mux = {32{1'bX}}; + // + endcase + + +endmodule |