25.2.8 UsingDMA
这样一句话：
Not all registers need to be read. The trigger timing is suchthat the DMA controller starts reading
MPY32 RES0 when its ready, and that the MPY32 RES3 can be read exactly in the clock cycle when it is
available to allow fastest access via DMA.
问题是：现在我要有 MPY16x16，在结果寄存器中RES0和RES1中的值传到flash中，而不需要RES2和RES3的值传到Flash中去，我应该怎么设置？
