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| //Encoder section of hamming 3
`timescale 100 ps/ 100ps
`ifdef SYNTHESIS
module encoder(parity,
state
);
`else
module encoder_rtl(parity,
state
);
`endif
parameter N = 4;
parameter M = 3;
input [N-1:0] state;
output [M-1:0] parity;
generate
begin
genvar i;
for (i = 0; i <M; i = i + 1)
begin : calc_parity
assign parity[i] = calculate_parity(state,i);
end
end
endgenerate
function automatic calculate_parity (input [N-1:0] state,//states in the input FSM
input [M-1:0] i//parity bit representation
);
begin
reg [0:56]parity_table[0:5] = '{ 57'b1_0101_0101_0101_0101_0101_0101_0101_0110_1010_1010_1010_1101_0101_1011,//0
57'b1_1001_1001_1001_1001_1001_1001_1001_1011_0011_0011_0011_0110_0110_1101,//1
57'b1_1110_0001_1110_0001_1110_0001_1110_0011_1100_0011_1100_0111_1000_1110,//2
57'b1_1111_1110_0000_0001_1111_1110_0000_0011_1111_1100_0000_0111_1111_0000,//3
57'b1_1111_1111_1111_1110_0000_0000_0000_0011_1111_1111_1111_1000_0000_0000,//4
57'b1_1111_1111_1111_1111_1111_1111_1111_1100_0000_0000_0000_0000_0000_0000};//5
reg [N-1:0] masked;
reg [N-1:0] masked_temp;
reg result;
result=0;
masked_temp = parity_table[i];
//$display("parity_table=%b,i=%d",parity_table[i],i);
masked = state & masked_temp;
//$display("masked=%b,state=%b,masked_temp=%b",masked,state,masked_temp);
result = ^masked;
//$display("results=%d",result);
return result;
end
endfunction
endmodule |