I couldn’t find any timing diagrams for the UART functionality. I wanted to know if in the uart1289 function, the CTS are RTS are active high or active low . I am looking to interface it with another micro-controller which uses CTS_n and RTS_n (active low) signals for flow control.
RTS and CTS are nRTS and nCTS on the imp, ie just like other TTL-level UARTs. CTS going high will stop the imp from sending.
Thanks Hugo - that was helpful.
Are both RTSn and CTSn high when not using UART? Or are they tristated?
If you’ve not configured the UART or any other peripheral on those pins, they are tristate. If you configure UART with NO_RTSCTS then flow control will be tristated, etc.