Hi Shim,

Your problem is that you have got an application note and trying to copy it into your application.

That is possible but then you shouldn't be asking questions.

Try to understand the data sheet of MT8888 and then try to develop your own schematic that suits your requirement.

You are straight asking why that pin/port is hooked up like that or so in the app. note. Ask the company engineer who launched the App.note.

Application notes are not to be copied exactly the same way (though it will yet work), in fact they are to make us understand the functionality of a particular device.

I would repeat, forget the application note and concentrate on the data sheet first.

Simon/