Subversion Repositories iso7816_3_master

/*

Author: Sebastien Riou (acapola)

Creation date: 17:16:40 01/09/2011

$LastChangedDate: 2011-02-13 16:20:10 +0100 (Sun, 13 Feb 2011) $

$LastChangedBy: acapola $

$LastChangedRevision: 15 $

$HeadURL: file:///svn/iso7816_3_master/iso7816_3_master/trunk/test/HexStringConversion.v $

This file is under the BSD licence:

Copyright (c) 2011, Sebastien Riou

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

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.

The names of contributors may not be used to endorse or promote products derived from this software without specific prior written permission.

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.

*/

function [7:0] hexString2Byte;

        input [15:0] byteInHexString;

        integer i;

        reg [7:0] hexDigit;

        reg [4:0] nibble;

        begin

                for(i=0;i<2;i=i+1) begin

                        nibble=5'b10000;//invalid

                        hexDigit=byteInHexString[i*8+:8];

                        if(("0"<=hexDigit)&&("9">=hexDigit))

                                nibble=hexDigit-"0";

                        if(("a"<=hexDigit)&&("f">=hexDigit))

                                nibble=10+hexDigit-"a";

                        if(("A"<=hexDigit)&&("F">=hexDigit))

                                nibble=10+hexDigit-"A";

                        if(nibble>15) begin

                                $display("Invalid input for hex conversion: '%s', hexDigit='%s' (%x), nibble=%d",byteInHexString,hexDigit,hexDigit,nibble);

                                $finish;

                        end

                        hexString2Byte[i*4+:4]=nibble;

                end

        end

endfunction

task getNextHexByte;

input [8*3*(256+5+1+2):0] bytesString;

input integer indexIn;

output reg [7:0] byteOut;

output integer indexOut;

reg [15:0] byteInHex;

begin

        byteInHex="  ";

        //$display("bytesString: %x",bytesString);      

        while((indexIn>=16)&((8'h0==byteInHex[15:8])|(8'h20==byteInHex[15:8]))) begin

                byteInHex=bytesString[(indexIn-1)-:16];

                indexIn=indexIn-8;

                //$display("indexIn: %d",indexIn);              

        end

        indexOut=indexIn-8;

        //$display("indexOut: %d, byteInHex: '%s' (%x)",indexOut, byteInHex, byteInHex);

        if((16'h0!=byteInHex) & (indexOut>=0) & (8'h20!=byteInHex[7:0])) begin

                byteOut=hexString2Byte(byteInHex);

                //$display("byteOut: %x",byteOut);

        end else begin

                indexOut=-1;

        end

end

endtask

task hexStringToBytes;

input [8*3*(256+5+1+2):0] bytesString;

output reg [8*(256+5+1+2):0] bytesOut;

output integer nBytes;

integer i;

reg [7:0] newByte;

begin

        nBytes=0;

        i=8*3*(256+5+1+2);

        //$display("bytesString: %x",bytesString);

        getNextHexByte(bytesString, i, newByte, i);

        while(i!=-1) begin

                //$display("i: %d, nBytes: %d, newByte: %x",i, nBytes, newByte);

                bytesOut[nBytes*8+:8]=newByte;

                nBytes=nBytes+1;

                getNextHexByte(bytesString, i, newByte, i);

        end

end

endtask