SIREG_DMA_CNTH
SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, (uint16_t)(xlen >> 16));
SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);