Problem with WriteEP buffer locations

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by ray@photosonix.com on Wed Oct 08 15:39:29 MST 2014
Using the LPC1345/6/7 USB Rom. Started out with NXPUSBLIB, then found a message saying it had been replaced by LPCOpen. But LPCOpen points me right back to LPCUSBLib. Don't think my real question is affected by this, but would appreciate advice on where to start.

The real question pertains to the LPC1345/6/7, I'm trying for a user defined device so I can use WINUSB. The writeups seem to say this is possible, but has anyone actually done it? Anyway, it seems I have to write an EP0 handler. The first setup message it gets is "get device descriptor", so I dutifully call WriteEP with a pointer to the device descriptor, but WriteEP calculates buffer addresses right over the buffer control words and moves the descriptor over them. Should WriteEP work right after Init, or am I supposed to change the buffer locations left by Init, or call another routine in between? Appreciate any advice.