c6748 upp UORI错误

请看一下下面TRM文档里对overflow的解释以及31.2.6.3 System Tuning Tips，和EDMA一起用时，把UPP的System Priority调高。

31.2.8.4 Underrun or Overflow (UOR) Event
This event occurs when the DMA channel fails to keep up with incoming or outgoing data on its associated interface channel. Typically, this error indicates that background system activity has interfered with normal operation of the peripheral. It does not occur simply when a channel is allowed to idle. After encountering this error, the uPP peripheral should be reset when this event occurs. This error should primarily occur when operating the uPP at high speed with significant system loading. To avoid this error, run the uPP at slower speeds or reduce background activity, such as non-uPP peripheral or DMA transactions. Additional tuning tips are given in Section 31.2.6.3.
www.ti.com/.../spruh79c.pdf