USB Library
USBCtrlEPAllowDataStage Function
Syntax
void USBCtrlEPAllowDataStage();
Preconditions

A control transfer (with data stage) should already be pending, if the firmware calls this function. Additionally, the firmware should have called either USBDeferOUTDataStage() or USBDeferINDataStage() at the start of the control transfer, if the firmware will be calling this function manually.

MLA - USB Library Help Version : 2.16
http://www.microchip.com/mla