DMA4_CCR_SEL_SRC_DST_SYNC
ccr |= DMA4_CCR_SEL_SRC_DST_SYNC(1);
ccr &= ~DMA4_CCR_SEL_SRC_DST_SYNC(1);
if (channel->reg_ccr & DMA4_CCR_SEL_SRC_DST_SYNC(1))