uart_hal_set_txfifo_empty_thr() function

Context of the HAL layer

The txfifo empty threshold to be set. If the `UART_TXFIFO_EMPTY` interrupt is enabled and the data length in txfifo is less than this value, it will generate `UART_TXFIFO_EMPTY` interrupt

Reset the UART rxfifo

Set the timeout value of the UART receiver

Configure the UART to send a number of break(NULL) chars

Write data into the UART txfifo

Get the UART source clock type

Configure the UART stop bit

Configure the UART data bit

Configure the UART parity mode

Configure the UART hardware flow control

Set the UART tx idle number

Set the UART rxfifo full threshold

Check if the UART rts flow control is enabled

Calculate uart symbol bit length, as defined in configuration.

Read data from the UART rxfifo

Reset the UART txfifo

Init the UART hal and set the UART to the default configuration.

Configure the UART AT cmd char detect function. When the receiver receives a continuous AT cmd char, it will produce a interrupt

Set the UART dtr signal active level

Set the UART software flow control

Configure the UART wake up function. Note that RXD cannot be input through GPIO Matrix but only through IO_MUX when use this function

Configure the UART mode

Configure the UART hardware to inverse the signals

Get the UART wakeup threshold configuration

Get the UART data bit configuration

Get the UART stop bit configuration

Get the UART parity mode configuration

Get the UART baud-rate configuration

Get the hw flow control configuration

Configure TX signal loop back to RX module, just for the testing purposes

Get UART maximum timeout threshold.