FX3传输速率达到40MbPS

大家好，我正试着在FX3板上开始开发，从提供的固件例子中学习。我想FX3生成一些数据，并通过USB发送到我的电脑。我不关心如何处理这些数据，现在我的兴趣是看传输比特率。在CyfxBulkSrCink实例中，设置了一对输入/输出端点（EP1默认，但我切换到EP6，以便具有更高带宽），然后为数据接收器创建通道中的DMA手册，并且为数据源创建DMA手动输出通道。E DMA手动输出信道并发送给主机。设置DMA手动信道的参数的代码如下：CYU3PDMACHANNEL CONtiCONT DMACFG；
DMACFG大小＝（UbSt=＝CyuU3PySuffi速度）？（大小×CyfxfxEpp-Burthl长度）：（大小）；
DCMACFG计数= CyfxxBulkSrcSikkgDMAB-BuffyCo计数；
DMACGF.PRODSCKID = CyfxxEppSuieldReSub；
DcMcF.C.
DMACGF.DMAMODE＝CYU-U3PY-DMAYMODEEY字节；
DMACFG通知= CYU-U3PYDMABCBYPRODYL事件；
CyfxBulkSrcSnkdCMAC；
正如你所看到的，我可以操纵大小（其中“大小”标识符在紧凑的“如果”语句是根据USB速度选择的数据包大小）和计数字段，以获得不同的性能。在论坛上，我读到，DMA缓冲区的大小可以增长到64K，但是任何替换DMACFG大小分配的右侧的值都不起作用（它允许我编译，但无法通过控制中心编程设备）。CyfFxBulkSrcSikkdDMAY-BuffyCalt的默认值为8，获得了约10MbPs的传输速率。将它提高到252（但不进一步，因为它不起作用）将传输速率改变到大约14MbPs。
使用CYFXBLKLPUTO示例，我可以达到40MbPS的传输速率。你能告诉我为什么会这么慢，即使转会只是一个方面吗？
P.S.作为软件应用程序，我使用默认的VisualStudio CPP应用程序。
谢谢，
姆林



     以下为原文
      Hi everybody,   
         I'm trying to get started in development on the FX3 board by learning from the firmware examples provided. I want the FX3 to generate some data and to send it via USB to my computer. I don't care about what to do with this data, for now my interest is to see the transfer bitrate. In the CyFxBulkSrcSink example a pair of IN/OUT endpoint is set (EP1 default, but I switched to EP6 in order to have higher bandwith), then a DMA MANUAL IN channel is created for data sink and a DMA MANUAL OUT channel is created for data source. A constant data pattern is continuously loaded into the DMA MANUAL OUT      channel and sent to the host.   
            
        The code to set the parameters to create the DMA MANUAL channel is the following:   
            
            
    CyU3PDmaChannelConfig_t dmaCfg;
    dmaCfg.size  = (u***Speed == CY_U3P_SUPER_SPEED) ? (size * CY_FX_EP_BURST_LENGTH) : (size);
     
    dmaCfg.count = CY_FX_BULKSRCSINK_DMA_BUF_COUNT;
    dmaCfg.prodSckId = CY_FX_EP_PRODUCER_SOCKET;
    dmaCfg.consSckId = CY_U3P_CPU_SOCKET_CONS;
    dmaCfg.dmaMode = CY_U3P_DMA_MODE_BYTE;
    dmaCfg.notification = CY_U3P_DMA_CB_PROD_EVENT;
    dmaCfg.cb = CyFxBulkSrcSinkDmaCallback;
     
    As you can see, I can manipulate the size (where the "size" identifier in the compact "if" statement is the packet size chosen according to the USB speed) and count fields to obtain different performances. Here on the forum I read that the size of DMA buffer can grow up to 64k, but any value I replace the right side of dmaCfg.size assignment with doesn't work (it lets me compile but fails programming the device by the control center). The default value of CY_FX_BULKSRCSINK_DMA_BUF_COUNT is 8, with which I obtain a transfer rate of about 10MBps. Raising it to 252 (but not any further, cause it doesn't work) changes the transfer rate to about 14MBps.
    Using the CyFxBulkLpAuto example I could reach a transfer rate of 40MBps. Can you tell me why it goes so slow, even if the transfer is one-side only?
    p.s. as software application I'm using the default visual studio cpp application provided.
     
    Thanks,
    mrain