$hash = { "ほげ" => 10, "ふが" => 5, "ぴき" => 30 };

for my $key (sort { $hash->{$b} <=> $hash->{$a} } keys %$hash) {
    print $key, ",", $hash->{$key}, "\n";
}

ぴき,30
ほげ,10
ふが,5