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-rw-r--r--src/rtl/sha256_w_mem.v331
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+//======================================================================
+//
+// sha256_w_mem_reg.v
+// -----------------
+// The W memory. This includes functionality to expand the
+// block into 64 23-bit words.
+//
+//
+// Author: Joachim Strombergson
+// Copyright (c) 2013 Secworks Sweden AB
+// 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 sha256_w_mem(
+ input wire clk,
+ input wire reset_n,
+
+ input wire init,
+
+ input wire [511 : 0] block,
+ input wire [5 : 0] addr,
+
+ output wire ready,
+ output wire [31 : 0] w
+ );
+
+
+ //----------------------------------------------------------------
+ // Internal constant and parameter definitions.
+ //----------------------------------------------------------------
+ parameter SHA256_ROUNDS = 63;
+
+ parameter CTRL_IDLE = 0;
+ parameter CTRL_UPDATE = 1;
+
+
+ //----------------------------------------------------------------
+ // Registers including update variables and write enable.
+ //----------------------------------------------------------------
+ reg [31 : 0] w_mem [0 : 63];
+ reg w_mem_we;
+ reg w0_w15_we;
+
+ reg [5 : 0] w_ctr_reg;
+ reg [5 : 0] w_ctr_new;
+ reg w_ctr_we;
+ reg w_ctr_inc;
+ reg w_ctr_set;
+
+ reg [1 : 0] sha256_w_mem_ctrl_reg;
+ reg [1 : 0] sha256_w_mem_ctrl_new;
+ reg sha256_w_mem_ctrl_we;
+
+
+ //----------------------------------------------------------------
+ // Wires.
+ //----------------------------------------------------------------
+ reg [31 : 0] w_tmp;
+ reg [31 : 0] w_new;
+
+ reg [5 : 0] w_addr;
+
+ reg [31 : 0] d1;
+ reg [31 : 0] d0;
+ reg [31 : 0] w_7;
+ reg [31 : 0] w_16;
+
+ reg w_init;
+ reg w_update;
+
+ reg ready_tmp;
+
+
+ //----------------------------------------------------------------
+ // Concurrent connectivity for ports etc.
+ //----------------------------------------------------------------
+ assign w = w_tmp;
+ assign ready = ready_tmp;
+
+
+ //----------------------------------------------------------------
+ // 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
+ w_ctr_reg <= 6'h00;
+
+ sha256_w_mem_ctrl_reg <= CTRL_IDLE;
+ end
+ else
+ begin
+
+ if (w0_w15_we)
+ begin
+ w_mem[00] <= block[511 : 480];
+ w_mem[01] <= block[479 : 448];
+ w_mem[02] <= block[447 : 416];
+ w_mem[03] <= block[415 : 384];
+ w_mem[04] <= block[383 : 352];
+ w_mem[05] <= block[351 : 320];
+ w_mem[06] <= block[319 : 288];
+ w_mem[07] <= block[287 : 256];
+ w_mem[08] <= block[255 : 224];
+ w_mem[09] <= block[223 : 192];
+ w_mem[10] <= block[191 : 160];
+ w_mem[11] <= block[159 : 128];
+ w_mem[12] <= block[127 : 96];
+ w_mem[13] <= block[95 : 64];
+ w_mem[14] <= block[63 : 32];
+ w_mem[15] <= block[31 : 0];
+ end
+
+ if (w_mem_we)
+ begin
+ w_mem[w_addr] <= w_new;
+ end
+
+ if (w_ctr_we)
+ begin
+ w_ctr_reg <= w_ctr_new;
+ end
+
+ if (sha256_w_mem_ctrl_we)
+ begin
+ sha256_w_mem_ctrl_reg <= sha256_w_mem_ctrl_new;
+ end
+ end
+ end // reg_update
+
+
+ //----------------------------------------------------------------
+ // external_addr_mux
+ //
+ // Mux for the external read operation. This is where we exract
+ // the W variable.
+ //----------------------------------------------------------------
+ always @*
+ begin : external_addr_mux
+ w_tmp = w_mem[addr];
+ end // external_addr_mux
+
+
+ //----------------------------------------------------------------
+ // w_7_logic
+ //----------------------------------------------------------------
+ always @*
+ begin : w_7_logic
+ reg [5 : 0] w_7_addr;
+
+ w_7_addr = w_ctr_reg - 6'h07;
+ w_7 = w_mem[w_7_addr];
+ end // w_7_logic
+
+
+ //----------------------------------------------------------------
+ // w_16_logic
+ //----------------------------------------------------------------
+ always @*
+ begin : w_16_logic
+ reg [5 : 0] w_16_addr;
+
+ w_16_addr = w_ctr_reg - 6'h10;
+ w_16 = w_mem[w_16_addr];
+ end // w_16_logic
+
+
+ //----------------------------------------------------------------
+ // d0_logic
+ //----------------------------------------------------------------
+ always @*
+ begin : d0_logic
+ reg [31 : 0] w_15;
+ reg [5 : 0] w_15_addr;
+
+ w_15_addr = w_ctr_reg - 6'h0f;
+ w_15 = w_mem[w_15_addr];
+
+ d0 = {w_15[6 : 0], w_15[31 : 7]} ^
+ {w_15[17 : 0], w_15[31 : 18]} ^
+ {3'b000, w_15[31 : 3]};
+ end // d0_logic
+
+
+ //----------------------------------------------------------------
+ // d1_logic
+ //----------------------------------------------------------------
+ always @*
+ begin : d1_logic
+ reg [31 : 0] w_2;
+ reg [5 : 0] w_2_addr;
+
+ w_2_addr = w_ctr_reg - 6'h02;
+ w_2 = w_mem[w_2_addr];
+
+ d1 = {w_2[16 : 0], w_2[31 : 17]} ^
+ {w_2[18 : 0], w_2[31 : 19]} ^
+ {10'b0000000000, w_2[31 : 10]};
+ end // d1_logic
+
+
+ //----------------------------------------------------------------
+ // w_schedule
+ //----------------------------------------------------------------
+ always @*
+ begin : w_schedule
+ w0_w15_we = 0;
+ w_mem_we = 0;
+ w_addr = 0;
+
+ w_new = d1 + w_7 + d0 + w_16;
+
+ if (w_init)
+ begin
+ w0_w15_we = 1;
+ end
+
+ if (w_update)
+ begin
+ w_mem_we = 1;
+ w_addr = w_ctr_reg;
+ end // if (w_update)
+ end // w_schedule
+
+
+ //----------------------------------------------------------------
+ // w_ctr
+ //
+ // W schedule adress counter. Counts from 0x10 to 0x3f and
+ // is used to expand the block into words.
+ //----------------------------------------------------------------
+ always @*
+ begin : w_ctr
+ w_ctr_new = 0;
+ w_ctr_we = 0;
+
+ if (w_ctr_set)
+ begin
+ w_ctr_new = 6'h10;
+ w_ctr_we = 1;
+ end
+
+ if (w_ctr_inc)
+ begin
+ w_ctr_new = w_ctr_reg + 6'h01;
+ w_ctr_we = 1;
+ end
+ end // w_ctr
+
+
+ //----------------------------------------------------------------
+ // sha256_w_mem_fsm
+ //
+ // Logic for the w shedule FSM.
+ //----------------------------------------------------------------
+ always @*
+ begin : sha256_w_mem_fsm
+ w_ctr_set = 0;
+ w_ctr_inc = 0;
+ w_init = 0;
+ w_update = 0;
+
+ ready_tmp = 0;
+
+ sha256_w_mem_ctrl_new = CTRL_IDLE;
+ sha256_w_mem_ctrl_we = 0;
+
+ case (sha256_w_mem_ctrl_reg)
+ CTRL_IDLE:
+ begin
+ ready_tmp = 1;
+
+ if (init)
+ begin
+ w_init = 1;
+ w_ctr_set = 1;
+
+ sha256_w_mem_ctrl_new = CTRL_UPDATE;
+ sha256_w_mem_ctrl_we = 1;
+ end
+ end
+
+ CTRL_UPDATE:
+ begin
+ w_update = 1;
+ w_ctr_inc = 1;
+
+ if (w_ctr_reg == SHA256_ROUNDS)
+ begin
+ sha256_w_mem_ctrl_new = CTRL_IDLE;
+ sha256_w_mem_ctrl_we = 1;
+ end
+ end
+ endcase // case (sha256_ctrl_reg)
+ end // sha256_ctrl_fsm
+endmodule // sha256_w_mem
+
+//======================================================================
+// EOF sha256_w_mem.v
+//======================================================================