DMA flow controller can solve unknown packet length problem

The peripheral that controls the length of the packet is known as the flow controller. The
flow controller is usually the DMAC, where the packet length is programmed by
software before the DMA channel is enabled. If the packet length is unknown when the
DMA channel is enabled, you can use either the source or destination peripherals as the
flow controller.

git no branch

兄弟，那个git no branch ,网上查到了
终于救回来了,
有个命令git help里看不到的 叫reflog
Git reflog 可以看到no branch 上 提交的tag list
然后找到 最后一个tag , git checkout xxxx 就可以了