sbox2.v

3des加密算法实现

`timescale 1ns/1ns
module  sbox2(addr, dout);
input	[1:6] addr;
output	[1:4] dout;
reg	[1:4] dout;

always @(addr) begin
    case ({addr[1], addr[6], addr[2:5]})	//synopsys full_case parallel_case
         0:  dout = 15;
         1:  dout =  1;
         2:  dout =  8;
         3:  dout = 14;
         4:  dout =  6;
         5:  dout = 11;
         6:  dout =  3;
         7:  dout =  4;
         8:  dout =  9;
         9:  dout =  7;
        10:  dout =  2;
        11:  dout = 13;
        12:  dout = 12;
        13:  dout =  0;
        14:  dout =  5;
        15:  dout = 10;

        16:  dout =  3;
        17:  dout = 13;
        18:  dout =  4;
        19:  dout =  7;
        20:  dout = 15;
        21:  dout =  2;
        22:  dout =  8;
        23:  dout = 14;
        24:  dout = 12;
        25:  dout =  0;
        26:  dout =  1;
        27:  dout = 10;
        28:  dout =  6;
        29:  dout =  9;
        30:  dout = 11;
        31:  dout =  5;

        32:  dout =  0;
        33:  dout = 14;
        34:  dout =  7;
        35:  dout = 11;
        36:  dout = 10;
        37:  dout =  4;
        38:  dout = 13;
        39:  dout =  1;
        40:  dout =  5;
        41:  dout =  8;
        42:  dout = 12;
        43:  dout =  6;
        44:  dout =  9;
        45:  dout =  3;
        46:  dout =  2;
        47:  dout = 15;

        48:  dout = 13;
        49:  dout =  8;
        50:  dout = 10;
        51:  dout =  1;
        52:  dout =  3;
        53:  dout = 15;
        54:  dout =  4;
        55:  dout =  2;
        56:  dout = 11;
        57:  dout =  6;
        58:  dout =  7;
        59:  dout = 12;
        60:  dout =  0;
        61:  dout =  5;
        62:  dout = 14;
        63:  dout =  9;

    endcase
    end

endmodule