STM8L串行半双工输出很奇怪

嗨，


我有USART半双工的问题。我的STM8L设备的输出太奇怪了。



前半部分（大约10个字节）来自主机。我的设备可以很好地接收。之后，主机等待立即从我的设备接收数据。

当我的设备开始向主机发送数据时，信号电平下降约300uSec。之后，等级回来了。这是什么 ？？？

我尝试使用连接的Tx-Rx进行全双工模式。看起来效果很好，但主机更改Rx和我的设备更改Tx之间发生了相同的级别下降。
我尝试将同一引脚上的GPIO模式设置为浮动输入和开漏输出。但结果是一样的。
我尝试使用重映射的USART（PC5-6）。但结果是一样的。
我有另一台不是STM的设备效果很好.....哎呀。

有谁知道我有什么问题吗？任何建议都是受欢迎的。

最好的祝福，
扎克
#stm8l #half- duplex #usart



以下为原文




Hi,


I have a problem with USART half duplex.  The output from my STM8L device is too strange.



The first half (about 10 bytes) is from host.  My device can receive this well.  After that, the host is wait to receive the data from my device immediately.

When my device starts to send back data to the host, the signal level is down about 300uSec.  After that, the level is back.  What is this ???

I try to do same thing with full duplex mode with connected Tx-Rx.  It looks like work well but same level down is happened between host changed Rx and my device changed Tx.
I try to set the mode of GPIO on same pin to both floating input and open drain output.  But the result is same.
I try to use remapped USART (PC5-6).  But the result is same.
I have another device that is not STM works well.....Oops.

Does anyone know what is wrong with me ?  Any suggestion is welcome.

Best Regards,
Zak  
#stm8l #half-duplex #usart