PICを作ろう ，インテルHEXを読む(5) ～昼休みにまったり進めるプロジェクト～

文字数制限に引っかかってしまうので、肝心なところだけ 

//
//  (c)2007 BakaOyaji

    begin : readandwrite
        ifp = $fopen( infile_name, "r" ) ;
        if( ifp == 0 ) begin
            error_code = `IHEX_ERROR_READOPEN;
            disable readandwrite ;
        end // if
        ofp = $fopen( outfile_name, "w" ) ;
        if( ofp == 0 ) begin
            error_code = `IHEX_ERROR_WRITEOPEN;
            disable readandwrite ;
        end
        byteperword = (bitperword+7)/8 ;  // need to check the varid range
        forever begin
            // perform a line
            if( $fgets( linebuf , ifp) == c_EOF ) begin
                error_code = `IHEX_ERROR_UNEXPECTED_EOF ;
                disable readandwrite ;
            end
            begin : find_comma // find ':'
                for( i = 0 ; i < `IHEX_MAXSTRLENGTH ; i = i+1 ) begin
                    if( linebuf [(i*8) +:8] == ":" ) begin
                        disable find_comma ; // found
                    end // if
                    if( linebuf [(i*8) +:8] == 8'h00 ) begin
                        error_code = `IHEX_ERROR_UNEXPECTEDFORMAT ;
                        disable readandwrite ;
                    end // if
                end // for
                // line is too long
                error_code = `IHEX_ERROR_UNEXPECTEDFORMAT ;
                disable readandwrite ;
            end // find_comma
            i = i -8 ;
            if( i < 2 ) begin
                error_code = `IHEX_ERROR_UNEXPECTEDFORMAT ;
                disable readandwrite ;
            end // if
            record_type = hex2int2( linebuf[(i*8) +: 16 ]) ;
            offset = hex2int4( linebuf[((i+2)*8) +: 32] ) ;
            record_length = hex2int2( linebuf[((i+6)*8) +: 16] ) ;
            if(    ( record_length == -1 )
                || (offset == -1 )
                || (record_type == -1 ) ) begin
                error_code = `IHEX_ERROR_UNEXPECTEDFORMAT ;
                disable readandwrite ;
            end // if
            case( record_type )
                `IHEX_REC_DATA : begin
                    $fwrite( ofp , "@%4h ", (segment + offset)/byteperword )  ;
                    repeat( record_length / byteperword ) begin
                        i = i - 2 * byteperword ;
                        if( i < 0 ) begin
                            error_code = `IHEX_ERROR_UNEXPECTEDFORMAT ;
                            disable readandwrite ;
                        end // if
                        j = i ;
                        repeat( byteperword ) begin // put a word
                            $fwrite( ofp , "%2s", linebuf[(j*8) +: 16] ) ;
                            j = j+2 ;
                        end // repeat
                        $fwrite( ofp , " ");
                    end // repeat
                    $fwrite( ofp, "\n" ) ;
                end
                  :
                  :
            endcase
        end // forever
    end // readandwrite