SD_ENABLE
SCSI_DMA->s_dma_ctrl = SD_ENABLE;
SCSI_DMA->s_dma_ctrl = SD_ENABLE|SD_OUT;
if (!poll && (SCSI_DMA->s_dma_ctrl & SD_ENABLE))
SCSI_DMA->s_dma_ctrl &= ~SD_ENABLE;
if (!poll && (SCSI_DMA->s_dma_ctrl & SD_ENABLE))
SCSI_DMA->s_dma_ctrl &= ~SD_ENABLE;