BASICS: Concept of glEP0buff

One thing you have to understand is that,

In vendor requests - we send Setup Packets to chose the application direction.

Setup packets have wValue and wIndex bits free if you want to receive some immediate data.

wLength is the length of data dumped onto the endpoint in the EP0 buffers from the computer to the host or vice-versa. If you want to pick this data up or put data on the buffer you do something like this:

CyU3PUsbSendEP0Data(wLength,glEp0Buffer, NULL);
CyU3PUsbGetEP0Data(wLength,glEp0Buffer, NULL);

Questions:

1.So does this transaction has to happen to complete a loop of communication protocol of some sort?
2. Will the pin up and down function actually need / or why would it actually need the fake EP0 buffer transfer.