www.pudn.com > rs-codec(255-223).rar > berlekamp.v
// -------------------------------------------------------------------------
//Berlekamp circuit for Reed-Solomon decoder
//Copyright (C) Tue Apr 2 17:07:10 2002
//by Ming-Han Lei(hendrik@humanistic.org)
//
//This program is free software; you can redistribute it and/or
//modify it under the terms of the GNU Lesser General Public License
//as published by the Free Software Foundation; either version 2
//of the License, or (at your option) any later version.
//
//This program is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
//GNU Lesser General Public License for more details.
//
//You should have received a copy of the GNU Lesser General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
// --------------------------------------------------------------------------
module rsdec_berl (lambda_out, omega_out, syndrome0, syndrome1, syndrome2, syndrome3, syndrome4, syndrome5, syndrome6, syndrome7, syndrome8, syndrome9, syndrome10, syndrome11, syndrome12, syndrome13, syndrome14, syndrome15, syndrome16, syndrome17, syndrome18, syndrome19, syndrome20, syndrome21, syndrome22, syndrome23, syndrome24, syndrome25, syndrome26, syndrome27, syndrome28, syndrome29, syndrome30, syndrome31,
D, DI, count, phase0, phase32, enable, clk, clrn);
input clk, clrn, enable, phase0, phase32;
input [7:0] syndrome0;
input [7:0] syndrome1;
input [7:0] syndrome2;
input [7:0] syndrome3;
input [7:0] syndrome4;
input [7:0] syndrome5;
input [7:0] syndrome6;
input [7:0] syndrome7;
input [7:0] syndrome8;
input [7:0] syndrome9;
input [7:0] syndrome10;
input [7:0] syndrome11;
input [7:0] syndrome12;
input [7:0] syndrome13;
input [7:0] syndrome14;
input [7:0] syndrome15;
input [7:0] syndrome16;
input [7:0] syndrome17;
input [7:0] syndrome18;
input [7:0] syndrome19;
input [7:0] syndrome20;
input [7:0] syndrome21;
input [7:0] syndrome22;
input [7:0] syndrome23;
input [7:0] syndrome24;
input [7:0] syndrome25;
input [7:0] syndrome26;
input [7:0] syndrome27;
input [7:0] syndrome28;
input [7:0] syndrome29;
input [7:0] syndrome30;
input [7:0] syndrome31;
input [7:0] DI;
input [5:0] count;
output [7:0] lambda_out;
output [7:0] omega_out;
reg [7:0] lambda_out;
reg [7:0] omega_out;
output [7:0] D;
reg [7:0] D;
integer j;
reg init, delta;
reg [4:0] L;
reg [7:0] lambda[31:0];
reg [7:0] omega[31:0];
reg [7:0] A[30:0];
reg [7:0] B[30:0];
wire [7:0] tmp0;
wire [7:0] tmp1;
wire [7:0] tmp2;
wire [7:0] tmp3;
wire [7:0] tmp4;
wire [7:0] tmp5;
wire [7:0] tmp6;
wire [7:0] tmp7;
wire [7:0] tmp8;
wire [7:0] tmp9;
wire [7:0] tmp10;
wire [7:0] tmp11;
wire [7:0] tmp12;
wire [7:0] tmp13;
wire [7:0] tmp14;
wire [7:0] tmp15;
wire [7:0] tmp16;
wire [7:0] tmp17;
wire [7:0] tmp18;
wire [7:0] tmp19;
wire [7:0] tmp20;
wire [7:0] tmp21;
wire [7:0] tmp22;
wire [7:0] tmp23;
wire [7:0] tmp24;
wire [7:0] tmp25;
wire [7:0] tmp26;
wire [7:0] tmp27;
wire [7:0] tmp28;
wire [7:0] tmp29;
wire [7:0] tmp30;
wire [7:0] tmp31;
always @ (tmp1) lambda_out = tmp1;
always @ (tmp3) omega_out = tmp3;
always @ (L or D or count)
// delta = (D != 0 && 2*L <= i);
if (D != 0 && count >= {L, 1'b0}) delta = 1;
else delta = 0;
rsdec_berl_multiply x0 (tmp0, B[30], D, lambda[0], syndrome0, phase0);
rsdec_berl_multiply x1 (tmp1, lambda[31], DI, lambda[1], syndrome1, phase0);
rsdec_berl_multiply x2 (tmp2, A[30], D, lambda[2], syndrome2, phase0);
rsdec_berl_multiply x3 (tmp3, omega[31], DI, lambda[3], syndrome3, phase0);
multiply x4 (tmp4, lambda[4], syndrome4);
multiply x5 (tmp5, lambda[5], syndrome5);
multiply x6 (tmp6, lambda[6], syndrome6);
multiply x7 (tmp7, lambda[7], syndrome7);
multiply x8 (tmp8, lambda[8], syndrome8);
multiply x9 (tmp9, lambda[9], syndrome9);
multiply x10 (tmp10, lambda[10], syndrome10);
multiply x11 (tmp11, lambda[11], syndrome11);
multiply x12 (tmp12, lambda[12], syndrome12);
multiply x13 (tmp13, lambda[13], syndrome13);
multiply x14 (tmp14, lambda[14], syndrome14);
multiply x15 (tmp15, lambda[15], syndrome15);
multiply x16 (tmp16, lambda[16], syndrome16);
multiply x17 (tmp17, lambda[17], syndrome17);
multiply x18 (tmp18, lambda[18], syndrome18);
multiply x19 (tmp19, lambda[19], syndrome19);
multiply x20 (tmp20, lambda[20], syndrome20);
multiply x21 (tmp21, lambda[21], syndrome21);
multiply x22 (tmp22, lambda[22], syndrome22);
multiply x23 (tmp23, lambda[23], syndrome23);
multiply x24 (tmp24, lambda[24], syndrome24);
multiply x25 (tmp25, lambda[25], syndrome25);
multiply x26 (tmp26, lambda[26], syndrome26);
multiply x27 (tmp27, lambda[27], syndrome27);
multiply x28 (tmp28, lambda[28], syndrome28);
multiply x29 (tmp29, lambda[29], syndrome29);
multiply x30 (tmp30, lambda[30], syndrome30);
multiply x31 (tmp31, lambda[31], syndrome31);
always @ (posedge clk or negedge clrn)
begin
// for (j = t-1; j >=0; j--)
// if (j != 0) lambda[j] += D * B[j-1];
if (~clrn)
begin
for (j = 0; j < 32; j = j + 1) lambda[j] <= 0;
for (j = 0; j < 31; j = j + 1) B[j] <= 0;
for (j = 0; j < 32; j = j + 1) omega[j] <= 0;
for (j = 0; j < 31; j = j + 1) A[j] <= 0;
L = 0;
D = 0;
end
else if (~enable)
begin
lambda[0] <= 1;
for (j = 1; j < 32; j = j +1) lambda[j] <= 0;
B[0] <= 1;
for (j = 1; j < 31; j = j +1) B[j] <= 0;
omega[0] <= 1;
for (j = 1; j < 32; j = j +1) omega[j] <= 0;
for (j = 0; j < 31; j = j + 1) A[j] <= 0;
L = 0;
D = 0;
end
else
begin
if (~phase0)
begin
if (~phase32) lambda[0] <= lambda[31] ^ tmp0;
else lambda[0] <= lambda[31];
for (j = 1; j < 32; j = j + 1)
lambda[j] <= lambda[j-1];
end
// for (j = t-1; j >=0; j--)
// if (delta) B[j] = lambda[j] *DI;
// else if (j != 0) B[j] = B[j-1];
// else B[j] = 0;
if (~phase0)
begin
if (delta) B[0] <= tmp1;
else if (~phase32) B[0] <= B[30];
else B[0] <= 0;
for (j = 1; j < 31; j = j + 1)
B[j] <= B[j-1];
end
// for (j = t-1; j >=0; j--)
// if (j != 0) omega[j] += D * A[j-1];
if (~phase0)
begin
if (~phase32) omega[0] <= omega[31] ^ tmp2;
else omega[0] <= omega[31];
for (j = 1; j < 32; j = j + 1)
omega[j] <= omega[j-1];
end
// for (j = t-1; j >=0; j--)
// if (delta) A[j] = omega[j] *DI;
// else if (j != 0) A[j] = A[j-1];
// else A[j] = 0;
if (~phase0)
begin
if (delta) A[0] <= tmp3;
else if (~phase32) A[0] <= A[30];
else A[0] <= 0;
for (j = 1; j < 31; j = j + 1)
A[j] <= A[j-1];
end
// if (delta) L = i - L + 1;
if ((phase0 & delta) && (count != -1)) L = count - L + 1;
//for (D = j = 0; j < t; j = j + 1)
// D += lambda[j] * syndrome[t-j-1];
if (phase0)
D = tmp0 ^ tmp1 ^ tmp2 ^ tmp3 ^ tmp4 ^ tmp5 ^ tmp6 ^ tmp7 ^ tmp8 ^ tmp9 ^ tmp10 ^ tmp11 ^ tmp12 ^ tmp13 ^ tmp14 ^ tmp15 ^ tmp16 ^ tmp17 ^ tmp18 ^ tmp19 ^ tmp20 ^ tmp21 ^ tmp22 ^ tmp23 ^ tmp24 ^ tmp25 ^ tmp26 ^ tmp27 ^ tmp28 ^ tmp29 ^ tmp30 ^ tmp31;
end
end
endmodule
module rsdec_berl_multiply (y, a, b, c, d, e);
input [7:0] a, b, c, d;
input e;
output [7:0] y;
wire [7:0] y;
reg [7:0] p, q;
always @ (a or c or e)
if (e) p = c;
else p = a;
always @ (b or d or e)
if (e) q = d;
else q = b;
multiply x0 (y, p, q);
endmodule
module multiply (y, a, b);
input [7:0] a, b;
output [7:0] y;
reg [7:0] y;
always @ (a or b)
begin
y[0] = (a[0] & b[0]) ^ (a[1] & b[7]) ^ (a[2] & b[6]) ^ (a[2] & b[7]) ^ (a[3] & b[5]) ^ (a[3] & b[6]) ^ (a[3] & b[7]) ^ (a[4] & b[4]) ^ (a[4] & b[5]) ^ (a[4] & b[6]) ^ (a[4] & b[7]) ^ (a[5] & b[3]) ^ (a[5] & b[4]) ^ (a[5] & b[5]) ^ (a[5] & b[6]) ^ (a[5] & b[7]) ^ (a[6] & b[2]) ^ (a[6] & b[3]) ^ (a[6] & b[4]) ^ (a[6] & b[5]) ^ (a[6] & b[6]) ^ (a[6] & b[7]) ^ (a[7] & b[1]) ^ (a[7] & b[2]) ^ (a[7] & b[3]) ^ (a[7] & b[4]) ^ (a[7] & b[5]) ^ (a[7] & b[6]);
y[1] = (a[0] & b[1]) ^ (a[1] & b[0]) ^ (a[1] & b[7]) ^ (a[2] & b[6]) ^ (a[3] & b[5]) ^ (a[4] & b[4]) ^ (a[5] & b[3]) ^ (a[6] & b[2]) ^ (a[7] & b[1]) ^ (a[7] & b[7]);
y[2] = (a[0] & b[2]) ^ (a[1] & b[1]) ^ (a[1] & b[7]) ^ (a[2] & b[0]) ^ (a[2] & b[6]) ^ (a[3] & b[5]) ^ (a[3] & b[7]) ^ (a[4] & b[4]) ^ (a[4] & b[6]) ^ (a[4] & b[7]) ^ (a[5] & b[3]) ^ (a[5] & b[5]) ^ (a[5] & b[6]) ^ (a[5] & b[7]) ^ (a[6] & b[2]) ^ (a[6] & b[4]) ^ (a[6] & b[5]) ^ (a[6] & b[6]) ^ (a[6] & b[7]) ^ (a[7] & b[1]) ^ (a[7] & b[3]) ^ (a[7] & b[4]) ^ (a[7] & b[5]) ^ (a[7] & b[6]);
y[3] = (a[0] & b[3]) ^ (a[1] & b[2]) ^ (a[2] & b[1]) ^ (a[2] & b[7]) ^ (a[3] & b[0]) ^ (a[3] & b[6]) ^ (a[4] & b[5]) ^ (a[4] & b[7]) ^ (a[5] & b[4]) ^ (a[5] & b[6]) ^ (a[5] & b[7]) ^ (a[6] & b[3]) ^ (a[6] & b[5]) ^ (a[6] & b[6]) ^ (a[6] & b[7]) ^ (a[7] & b[2]) ^ (a[7] & b[4]) ^ (a[7] & b[5]) ^ (a[7] & b[6]) ^ (a[7] & b[7]);
y[4] = (a[0] & b[4]) ^ (a[1] & b[3]) ^ (a[2] & b[2]) ^ (a[3] & b[1]) ^ (a[3] & b[7]) ^ (a[4] & b[0]) ^ (a[4] & b[6]) ^ (a[5] & b[5]) ^ (a[5] & b[7]) ^ (a[6] & b[4]) ^ (a[6] & b[6]) ^ (a[6] & b[7]) ^ (a[7] & b[3]) ^ (a[7] & b[5]) ^ (a[7] & b[6]) ^ (a[7] & b[7]);
y[5] = (a[0] & b[5]) ^ (a[1] & b[4]) ^ (a[2] & b[3]) ^ (a[3] & b[2]) ^ (a[4] & b[1]) ^ (a[4] & b[7]) ^ (a[5] & b[0]) ^ (a[5] & b[6]) ^ (a[6] & b[5]) ^ (a[6] & b[7]) ^ (a[7] & b[4]) ^ (a[7] & b[6]) ^ (a[7] & b[7]);
y[6] = (a[0] & b[6]) ^ (a[1] & b[5]) ^ (a[2] & b[4]) ^ (a[3] & b[3]) ^ (a[4] & b[2]) ^ (a[5] & b[1]) ^ (a[5] & b[7]) ^ (a[6] & b[0]) ^ (a[6] & b[6]) ^ (a[7] & b[5]) ^ (a[7] & b[7]);
y[7] = (a[0] & b[7]) ^ (a[1] & b[6]) ^ (a[1] & b[7]) ^ (a[2] & b[5]) ^ (a[2] & b[6]) ^ (a[2] & b[7]) ^ (a[3] & b[4]) ^ (a[3] & b[5]) ^ (a[3] & b[6]) ^ (a[3] & b[7]) ^ (a[4] & b[3]) ^ (a[4] & b[4]) ^ (a[4] & b[5]) ^ (a[4] & b[6]) ^ (a[4] & b[7]) ^ (a[5] & b[2]) ^ (a[5] & b[3]) ^ (a[5] & b[4]) ^ (a[5] & b[5]) ^ (a[5] & b[6]) ^ (a[5] & b[7]) ^ (a[6] & b[1]) ^ (a[6] & b[2]) ^ (a[6] & b[3]) ^ (a[6] & b[4]) ^ (a[6] & b[5]) ^ (a[6] & b[6]) ^ (a[7] & b[0]) ^ (a[7] & b[1]) ^ (a[7] & b[2]) ^ (a[7] & b[3]) ^ (a[7] & b[4]) ^ (a[7] & b[5]);
end
endmodule