Enable Auto Control RS485 Feature of SC16IS740

[gagandeep_singh]

Hello NXP Team 

We are trying to implement a Auto Control RS485 of SC16IS740, but its not working. Currently SC16IS740 (TPSOP-16) is connected with Processor and interfaced through SPI interface. on other side SC16IS740 is connected with  SN65HVD72D  ( RS485 half duplex Transreceiver) through UART interface. We are enabling Auto RTS to implement the Auto Control Feature, after configuration we are able to Transmit the Data but Receving is not happening ( RTS is not getting low after transmission) , Can you please support on this and Provide the your testing sch and Resgister configuration for this and Let me know if any further inputs are required from our side. 

[lisettelozano]

Hello,

As mentioned in the datasheet, to use the auto RS-485 RTS mode the software would have to disable the hardware flow control function. Could you please share your register settings? Especially, the setting on the EFCR register. Also, can you please share the schematic of the connection between the SC16IS740 and the RS-485 transceiver?

Unfortunately, we do not have any schematic or register configuration for the SC16IS740 to share; I apologize for this inconvenience.

Have a great day,

Paulina