control endpoint 发送，接收数据 返回fasle ， lastError = 997， 抓包查看 Control Transfer (UP) XXXXXXXXX 1. Device: FX3 Status: 0xc0000004
USBD_STATUS_STALL_PID 0xC0000004 The device returned a stall packet identifier (defined for backward compatibility with the USB 1.0)
需要在CyU3PUsbRegisterSetupCallback的注册回调函数中去定义相应的Req Type ，Target以及Req code等等，然后进行处理，否则就返回error。。
https://community.cypress.com/thread/13031?start=0&tstart=0
Did you make sure that the device responds properly to the vendor command? Is it handled in your firmware? The 997 error iscaused if the device does not send anything.
========
FX3/CX3 简介
https://blog.csdn.net/a379039233/article/details/53425202
FX3/CX3 DMA Overview
http://www.voidcn.com/article/p-faedbthz-dk.html