用LPC2148的BULK传输，DMA方式

只看该作者 · 2007-10-12 10:26

请各位帮忙看看，运用DMA在批量传输方式中能够正常接收，无法正常发送，是什么原因？
void USB_EndPoint2 (DWORD event) {

USB_DMA_DESCRIPTOR DD;

//从PC接收数据,能正常接收数据
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 */
}
}
}
////////////////////////////////////发送数据到PC，不能发送数据
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 */
}
}
}
}

程序是使用keil自带的usbaudio程序代码改过来的，现在接收应该正常了，但发送PC接收不到任何数据，我把接收部分单独提出来也没有用，象这样也收不到数据：
void USB_EndPoint1 (DWORD event) {
USB_DMA_DESCRIPTOR DD;
DWORD DataLen;
BYTE DBuf[0x10];
switch (event) {
case USB_EVT_IN: //控制传输来自PC的输入发送传输字节的总长度
break;
case USB_EVT_OUT: //控制传输来自PC的输出接收所有命令
// 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;
}
}

用LPC2148的BULK传输，DMA方式

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