I have got the post on mangOH forum:
I want to use RTS/CTS lines to control flow on my designed IoT card. Unfortunately I cannot do it. All technical drawings show RTS/CTS lines, so I have assumed, both UARTS are 4-wire. My assumption was wrong. After your last response, I checked architecture of WP8548, WP7502, WP7504. All 3 processors has got 2 UARTS. UART1 is 8-wire and UART2 is only 2-wire.
I cannot use RTS/CTS lines because:
FX30 has got UART2 on IoT card, so only Rx,Tx are available (no RTS/CTS). FX30S has got RS232 on the back based on UART1, but lines RTS/CTS are dead/unresponsive.
I have got UART1 on mangOH green on IoT0 or IoT1 slot. But I can control only RTS line. I cannot read status of CTS.
mangOH Red has got UART1 on IoT slot, but I don’t know if I can control RTS/CTS lines, because I don’t have the board.
I can NOT use RTS/CTS lines on my IoT card because it will not be working. FX30 has not got MUX to redirect UART1 to IoT. So it will not be working because of design of FX30. mangOH green thinks that CTS line is always set, so my IoT will not be working.