Edit in JSFiddle

<div ng-controller="myCtrl">
  {{ data }}
  <my-directive></my-directive>
</div>

var myApp = angular.module('myApp', []);

myApp.controller('myCtrl', ['$scope', function ($scope) {
  $scope.data = 'AAA';
}]);

myApp.directive('myDirective', function() {
  return {
    restrict: 'E',
    scope: false,
    template: '<div>{{data}}</div>',
    link: function(scope) {
      scope.data = 'BBB';
    }
  }
});