Usb bulk

using the BULK transfer, DMA mode
Please help us to see, the use of DMA transfer in batch mode to the normal reception can not be delivered, why?
void USB_EndPoint2 (DWORD event) {

USB_DMA_DESCRIPTOR DD;

/ / Receive data from the PC can receive data properly
if (event & (USB_EVT_OUT_DMA_EOT) | (USB_EVT_OUT_DMA_NDR)) {
/ * End of Transfer or New Descriptor Request * /
DD.BufAdr = (DWORD) DataBuf + 2 * DataIn; / * DMA Buffer Address * /
DD.BufLen = B_S; / * DMA Packet Count * /
DD.MaxSize = 64; / * Must be 0 for Iso Transfer * /
DD.InfoAdr = (DWORD) InfoBuf; / * Packet Info Buffer Address * /
DD.Cfg.Val = 0; / * Initial DMA Configuration * /
DD.Cfg.Type.IsoEP = 0; / * Iso Endpoint * /
USB_DMA_Setup (0x02, & DD); / * Setup DMA * /
USB_DMA_Enable (0x02); / * Enable DMA * /
} if (event & USB_EVT_OUT_DMA_EOT) {
/ * End of Transfer * /
if (USB_DMA_BufAdr (0x02)! = ((DWORD) DataBuf + 2 * DataIn)) {
/ * Data Available * /
DataIn + = 64; / * Update Data In Index * /
DataIn & = B_S - 1; / * Adjust Data In Index * /
if (DataIn & (B_S - 1)) == B_S / 2) {
DataRun = 1; / * Data Stream running * /
} }
} //////////////////////////////////// Send data to a PC, can not send data
if (DataRun == 1)
{ if (event & (USB_EVT_IN_DMA_EOT) | (USB_EVT_IN_DMA_NDR)) {
DD.BufAdr = (DWORD) DataBuf + 2 * DataOut; / * DMA Buffer Address * /
DD.BufLen = B_S; / * DMA Packet Count * /
DD.MaxSize = 64; / * Must be 0 for Iso Transfer * /
DD.InfoAdr = (DWORD) InfoBuf; / * Packet Info Buffer Address * /
DD.Cfg.Val = 1; / * Initial DMA Configuration * /
DD.Cfg.Type.IsoEP = 0; / * Iso Endpoint * /
USB_DMA_Setup (0x82, & DD); / * Setup DMA * /
USB_DMA_Enable (0x82); / * Enable DMA * /
} if (event & USB_EVT_IN_DMA_EOT) {
DataOut + = 64; / * Update Data In Index * /
DataOut & = B_S - 1; / * Adjust Data In Index * /
if (DataIn == DataOut) {
DataRun = 0; / * Data Stream running * /
DataOut = DataIn; / * Initialize Data Indexes * /
} }
} }

Program is to use keil comes usbaudio code change overnight, and now receives should be normal, but the PC can not receive any data to send, I receive the parts separately to no avail, as such can not receive data:
void USB_EndPoint1 (DWORD event) {
USB_DMA_DESCRIPTOR DD;
DWORD DataLen;
BYTE DBuf [0x10];
switch (event) {
case USB_EVT_IN: / / control the transmission of input from the PC to send the total length of bytes transferred
break;
case USB_EVT_OUT: / / control the transmission output from the PC to receive all commands
/ / USB_ClrStallEP (USB_ENDPOINT_OUT (1));
DataLen = 0;
DataLen = USB_ReadEP (USB_ENDPOINT_OUT (1), DBuf);
DD.BufAdr = (DWORD) DataBuf; / * DMA Buffer Address * /
DD.BufLen = B_S; / * DMA Packet Count * /
DD.MaxSize = 64; / * Must be 0 for Iso Transfer * /
DD.InfoAdr = (DWORD) InfoBuf; / * Packet Info Buffer Address * /
DD.Cfg.Val = 1; / * Initial DMA Configuration * /
DD.Cfg.Type.IsoEP = 0; / * Iso Endpoint * /
USB_DMA_Setup (0x82, & DD); / * Setup DMA * /
USB_DMA_Enable (0x82); / * Enable DMA * /
break;
} }