如题，驱动和BSP皆由友善官网提供，应用程序CreateFile()成功，DeviceIoControl()成功，使用DMA模式SPI传输数据，想用WriteFile()连续传送8个字节，用示波器抓包发现只有第一个byte是正确的，后面的7个都是误码，请问是什么原因？
关键代码如下：
h_spi = CreateFile(TEXT("SPI1:"), GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
DWORD dwWritenSize = 0;
DWORD dwWritenData[8] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08};
SET_CONFIG Set_SPI_Config;
Set_SPI_Config.dwMode = SPI_MASTER_MODE;
...
Set_SPI_Config.bUseTxDMA = TRUE;
DeviceIoControl(h_spi, SPI_IOCTL_SET_CONFIG, &Set_SPI_Config, sizeof(Set_SPI_Config), NULL, 0, NULL, NULL);
DeviceIoControl(h_spi, SPI_IOCTL_START, NULL, 0, NULL, 0, NULL, NULL);
WriteFile(h_spi, dwWritenData, 8, &dwWritenSize, NULL);
