espltd,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
</style>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script>
$(function() {
$("#area").on("input", function() {
var text = this.value;
if (/^(?:\d{11};)+$/.test(text)) return;
text = text.replace(/\D/g, "").match(/\d{1,11}/g);
this.value = text ? text.join(";") : ""
})
});
</script>
</head>
<body>
<textarea id="area" name="" cols="12" rows="7"></textarea>
</body>
</html>