You will need to learn about ampersand-encoding and XML then. I guess that 
 is already encoded and the 
 stands for the character \x0A in Perl parlance. So you will need to change your initial string to:

my $string="Johnson Controls Automotive Electronics\x0APackage: GMLAN 
+3.1 - Single Channel\x0AMicro: uPD70F3524\x0ACompiler: Green Hills 5.
+1.7-BD1110030";
[download]

or, in a more sensible fashion:

my $string= join "\n", 
    "Johnson Controls Automotive Electronics",
    "Package: GMLAN 3.1 - Single Channel",
    "Micro: uPD70F3524",
    "Compiler: Green Hills 5.1.7-BD1110030";
[download]

I guess that the original text contains line breaks and you want to preserve them.