RS485 mode configuration
| RS485_EN | Set this bit to choose the rs485 mode. | 
| DL0_EN | Set this bit to delay the stop bit by 1 bit. | 
| DL1_EN | Set this bit to delay the stop bit by 1 bit. | 
| RS485TX_RX_EN | Set this bit to enable receiver could receive data when the transmitter is transmitting data in rs485 mode. | 
| RS485RXBY_TX_EN | 1’h1: enable rs485 transmitter to send data when rs485 receiver line is busy. | 
| RS485_RX_DLY_NUM | This register is used to delay the receiver’s internal data signal. | 
| RS485_TX_DLY_NUM | This register is used to delay the transmitter’s internal data signal. |