在半双工通信中控制TX_EN GPIO的最佳方法是什么？

使用HARMony 2.01b、PIC32MZ2048EFG144以及Harmony UART驱动程序，控制TX_EN GPIO的最佳方式（代码中的最佳位置在哪里）是什么？例如，当使用MAX13430E RS-485收发信机时，需要在代码填充PIC32 UART TX FIFO之前启用它的发射机，并在PIC32 UART移出最后一位数据以将收发信机放回接收模式之后禁用它的发射机。当发送FIFO为空时，会生成一个发送中断；但是，我正在考虑将其设置为00，以便在FIFO中至少有一个空白空间时得到中断。然而，无论何时生成此中断，代码都必须等待FIFO完全清空，然后UxTSR（发射机移位寄存器）完全清空，然后才关闭TX_EN GPIO。我不想使用一些轮询方法来阻止固件的其他部分的执行。和声是否有一种标准的处理方法（在UART驱动程序中还是作为高级服务）？



      以下为原文

    Using Harmony 2.01b, PIC32MZ2048EFG144, and the Harmony UART driver, what is the best way (where is the best place in the code) to control a TX_EN GPIO?

For example, when using a MAX13430E RS-485 transceiver, its transmitter needs to be enabled just before code fills the PIC32 UART TX FIFO, and disabled after the PIC32 UART shifts out the last bit of data to put the transceiver back into receive mode.

Currently, I have UTXISEL<1:0> set to 01 meaning transmit interrupt is generated when transmit FIFO is empty; however I am thinking of setting it to 00 to get an interrupt whenever there is at least one empty space in the FIFO. Nevertheless, regardless when this interrupt is generated, code must still wait for the FIFO to empty out completely, followed by UxTSR (the transmitter shift register) emptying out completely, before turning off the TX_EN GPIO. I do not want to use some polling method that blocks execution of other parts of the firmware. Does Harmony have a standard way of handling this (either in the UART driver or as a higher level service)?