i m trying to implement USB based Mass Storage Device as a RAM.As there are two modes in USB slave mode and DMA mode.My code is working well in SLAVE mode.In DMA mode when i start writing file on RAM after receiving two chunks of 64 byte each successfully i receive third chunk with sometimes 35 bytes or 64 byte. I m using teledyne lecroy mercury t2 usb packet analyzer.After monitoring on analyzer i came to know that while transmitting last chunk i receive bad turnaround/timeout error.How do i resolve this error? I m implementing MSC on lpc1768.