Serial flow control

The RTS and CTS device pins provide RTS and/or CTS flow control. CTS flow control signals the host to stop sending serial data to the device. RTS flow control lets the host signal the device so it will not send the data in the serial transmit buffer out the UART. Use the D6 and D7 commands to enable RTS and CTS flow control.

CTS flow control

CTS flow control is enabled by default; you can disable it with the D7 command. When the serial receive buffer fills with the number of bytes specified by the FT parameter, the device de-asserts CTS (sets it high) to signal the host device to stop sending serial data. The device re-asserts CTS when less than FT-16 bytes are in the UART receive buffer; for more information, see FT (Flow Control Threshold).

RTS flow control

If you send the D6 command to enable RTS flow control, the device does not send data in the serial transmit buffer out the DOUT pin as long as RTS is de-asserted (set high). Do not de-assert RTS for long periods of time or the serial transmit buffer will fill. If the device receives an RF data packet and the serial transmit buffer does not have enough space for all of the data bytes, it discards the entire RF data packet.