2. In what kind of operation problems appear, and how to reproduce the problem ?（什么样的操作步骤问题会出现，是否是稳定复现，如何复现问题？）
{
In order to use RS-485 PHY or so ons it's good to have event when Transmit is actual finished at the physical pin. It required for switch line driver from Tx to Rx mode. But there are no the event and no a mode to use RTS/CTS pins. Therefore UART is strict limited in using PHY layers. Actually it's not UART, it is UART-TTL-only interface.
1. SDK version（SDK 版本）
{ V2129 }
2. In what kind of operation problems appear, and how to reproduce the problem ?（什么样的操作步骤问题会出现，是否是稳定复现，如何复现问题？）
{ In order to use RS-485 PHY or so ons it's good to have event when Transmit is actual finished at the physical pin. It required for switch line driver from Tx to Rx mode. But there are no the event and no a mode to use RTS/CTS pins. Therefore UART is strict limited in using PHY layers. Actually it's not UART, it is UART-TTL-only interface.
}