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authorJoachim StroĢˆmbergson <joachim@secworks.se>2014-02-22 08:07:35 +0100
committerJoachim StroĢˆmbergson <joachim@secworks.se>2014-02-22 08:07:35 +0100
commitc6e33cb7819fab39cb29789914a311cda6a47068 (patch)
tree635e62c6115620b650dc7c94d3e8275a25aa3e9e /src
parent7340c6e798937b8444344131801e54cb2f27365b (diff)
Changed W-memory into sliding window. This also affected interface and integration in the core.
Diffstat (limited to 'src')
-rw-r--r--src/rtl/sha256_core.v12
-rw-r--r--src/rtl/sha256_w_mem.v207
2 files changed, 84 insertions, 135 deletions
diff --git a/src/rtl/sha256_core.v b/src/rtl/sha256_core.v
index bb7995e..5035954 100644
--- a/src/rtl/sha256_core.v
+++ b/src/rtl/sha256_core.v
@@ -144,7 +144,7 @@ module sha256_core(
wire [31 : 0] k_data;
reg w_init;
- wire w_ready;
+ reg w_next;
wire [31 : 0] w_data;
@@ -161,12 +161,10 @@ module sha256_core(
.clk(clk),
.reset_n(reset_n),
- .init(w_init),
-
.block(block),
- .addr(t_ctr_reg),
- .ready(w_ready),
+ .init(w_init),
+ .next(w_next),
.w(w_data)
);
@@ -408,6 +406,7 @@ module sha256_core(
//----------------------------------------------------------------
// t_ctr
+ //
// Update logic for the round counter, a monotonically
// increasing counter with reset.
//----------------------------------------------------------------
@@ -432,6 +431,7 @@ module sha256_core(
//----------------------------------------------------------------
// sha256_ctrl_fsm
+ //
// Logic for the state machine controlling the core behaviour.
//----------------------------------------------------------------
always @*
@@ -446,6 +446,7 @@ module sha256_core(
ready_flag = 0;
w_init = 0;
+ w_next = 0;
t_ctr_inc = 0;
t_ctr_rst = 0;
@@ -490,6 +491,7 @@ module sha256_core(
CTRL_ROUNDS:
begin
+ w_next = 1;
state_update = 1;
t_ctr_inc = 1;
diff --git a/src/rtl/sha256_w_mem.v b/src/rtl/sha256_w_mem.v
index 758e3bd..4a5b759 100644
--- a/src/rtl/sha256_w_mem.v
+++ b/src/rtl/sha256_w_mem.v
@@ -1,14 +1,13 @@
//======================================================================
//
-// sha256_w_mem_reg.v
-// -----------------
-// The W memory. This includes functionality to expand the
-// block into 64 23-bit words.
+// sha256_w_mem_regs.v
+// -------------------
+// The W memory. This version uses 16 32-bit registers as a sliding
+// window to generate the 64 words.
//
//
-// Author: Joachim Strombergson
-// Copyright (c) 2013 Secworks Sweden AB
-// All rights reserved.
+// Author: Joachim Strombergson.
+// Copyright (c) 2014
//
// Redistribution and use in source and binary forms, with or
// without modification, are permitted provided that the following
@@ -41,12 +40,10 @@ 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,
+ input wire init,
+ input wire next,
output wire [31 : 0] w
);
@@ -54,8 +51,6 @@ module sha256_w_mem(
//----------------------------------------------------------------
// Internal constant and parameter definitions.
//----------------------------------------------------------------
- parameter SHA256_ROUNDS = 63;
-
parameter CTRL_IDLE = 0;
parameter CTRL_UPDATE = 1;
@@ -63,15 +58,13 @@ module sha256_w_mem(
//----------------------------------------------------------------
// Registers including update variables and write enable.
//----------------------------------------------------------------
- reg [31 : 0] w_mem [0 : 63];
- reg w_mem_we;
- reg w0_w15_we;
+ reg [31 : 0] w_mem [0 : 15];
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 w_ctr_rst;
reg [1 : 0] sha256_w_mem_ctrl_reg;
reg [1 : 0] sha256_w_mem_ctrl_new;
@@ -83,30 +76,19 @@ module sha256_w_mem(
//----------------------------------------------------------------
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;
+ reg mem_update;
//----------------------------------------------------------------
// 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.
@@ -115,14 +97,12 @@ module sha256_w_mem(
begin : reg_update
if (!reset_n)
begin
- w_ctr_reg <= 6'h00;
-
+ w_ctr_reg <= 6'h00;
sha256_w_mem_ctrl_reg <= CTRL_IDLE;
end
else
begin
-
- if (w0_w15_we)
+ if (init)
begin
w_mem[00] <= block[511 : 480];
w_mem[01] <= block[479 : 448];
@@ -141,10 +121,24 @@ module sha256_w_mem(
w_mem[14] <= block[63 : 32];
w_mem[15] <= block[31 : 0];
end
-
- if (w_mem_we)
+ else if (mem_update)
begin
- w_mem[w_addr] <= w_new;
+ w_mem[00] <= w_mem[01];
+ w_mem[01] <= w_mem[02];
+ w_mem[02] <= w_mem[03];
+ w_mem[03] <= w_mem[04];
+ w_mem[04] <= w_mem[05];
+ w_mem[05] <= w_mem[06];
+ w_mem[06] <= w_mem[07];
+ w_mem[07] <= w_mem[08];
+ w_mem[08] <= w_mem[09];
+ w_mem[09] <= w_mem[10];
+ w_mem[10] <= w_mem[11];
+ w_mem[11] <= w_mem[12];
+ w_mem[12] <= w_mem[13];
+ w_mem[13] <= w_mem[14];
+ w_mem[14] <= w_mem[15];
+ w_mem[15] <= w_new;
end
if (w_ctr_we)
@@ -168,95 +162,53 @@ module sha256_w_mem(
//----------------------------------------------------------------
always @*
begin : external_addr_mux
- w_tmp = w_mem[addr];
+ if (w_ctr_reg < 16)
+ begin
+ w_tmp = w_mem[w_ctr_reg[3 : 0]];
+ mem_update = 0;
+ end
+ else
+ begin
+ w_tmp = w_new;
+ mem_update = 1;
+ end
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
+ // w_new_logic
+ //
+ // Logic that calculates the next value to be inserted into
+ // the sliding window of the memory.
//----------------------------------------------------------------
always @*
- begin : w_schedule
- w0_w15_we = 0;
- w_mem_we = 0;
- w_addr = 0;
+ begin : w_new_logic
+ reg [31 : 0] w_0;
+ reg [31 : 0] w_1;
+ reg [31 : 0] w_9;
+ reg [31 : 0] w_14;
+ reg [31 : 0] d0;
+ reg [31 : 0] d1;
+
+ w_0 = w_mem[0];
+ w_1 = w_mem[1];
+ w_9 = w_mem[9];
+ w_14 = w_mem[14];
+
+ d0 = {w_1[6 : 0], w_1[31 : 7]} ^
+ {w_1[17 : 0], w_1[31 : 18]} ^
+ {3'b000, w_1[31 : 3]};
- w_new = d1 + w_7 + d0 + w_16;
+ d1 = {w_14[16 : 0], w_14[31 : 17]} ^
+ {w_14[18 : 0], w_14[31 : 19]} ^
+ {10'b0000000000, w_14[31 : 10]};
- 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_new = d1 + w_9 + d0 + w_0;
+ end // w_new_logic
+
//----------------------------------------------------------------
// w_ctr
- //
// W schedule adress counter. Counts from 0x10 to 0x3f and
// is used to expand the block into words.
//----------------------------------------------------------------
@@ -265,9 +217,9 @@ module sha256_w_mem(
w_ctr_new = 0;
w_ctr_we = 0;
- if (w_ctr_set)
+ if (w_ctr_rst)
begin
- w_ctr_new = 6'h10;
+ w_ctr_new = 6'h00;
w_ctr_we = 1;
end
@@ -286,12 +238,8 @@ module sha256_w_mem(
//----------------------------------------------------------------
always @*
begin : sha256_w_mem_fsm
- w_ctr_set = 0;
+ w_ctr_rst = 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;
@@ -299,13 +247,9 @@ module sha256_w_mem(
case (sha256_w_mem_ctrl_reg)
CTRL_IDLE:
begin
- ready_tmp = 1;
-
if (init)
begin
- w_init = 1;
- w_ctr_set = 1;
-
+ w_ctr_rst = 1;
sha256_w_mem_ctrl_new = CTRL_UPDATE;
sha256_w_mem_ctrl_we = 1;
end
@@ -313,10 +257,12 @@ module sha256_w_mem(
CTRL_UPDATE:
begin
- w_update = 1;
- w_ctr_inc = 1;
-
- if (w_ctr_reg == SHA256_ROUNDS)
+ if (next)
+ begin
+ w_ctr_inc = 1;
+ end
+
+ if (w_ctr_reg == 6'h3f)
begin
sha256_w_mem_ctrl_new = CTRL_IDLE;
sha256_w_mem_ctrl_we = 1;
@@ -324,6 +270,7 @@ module sha256_w_mem(
end
endcase // case (sha256_ctrl_reg)
end // sha256_ctrl_fsm
+
endmodule // sha256_w_mem
//======================================================================