WhyCan Forum(哇酷开发者社区)

@shaoxi2010
请问是如何修改的fifo为1/2触发？我改了之后又立马读，发现改不动。看了用户手册，它是这样说的：
“TFT
TX Empty Trigger
Writes have no effect when THRE_MODE_USER = Disabled. This is used to
select the empty threshold level at which the THRE Interrupts are
generated when the mode is active. lt also determines when the
dma_tx_req_n signal is asserted when in certain modes of operation.
00: FIFO empty
01: 2 characters in the FIFO
10: FIFO 1/4 full
11: FIFO 1/2 full”