TextField keyup iOS 7

I'm using sencha 2.3 and developing an iOS 7 app. The keyup event isn't returning any keycodes. I'm using the following listener:

Code:

textfield: {
    keyup: function (f, e) {
        console.log(e.event.keyCode);
        if (e.event.keyCode == 13) {
            this.validate();
        }
    },
},

Has anyone else had this issue?