[Hilo] How do RTS-CTS work for hardware flow control?


#1

[Hilo] What’s the RTS-CTS connection? How does it work when in H/W flow control?

Answer: CTS_HILO is an output from HILO and an input to RTS_HOST. HILO uses CTS to signal HOST to stop sending.
CTS_HOST is an output from HOST and an input to RTS_HILO. HILO stops sending to HOST when it sees that RTS is asserted

For example, seen from HILO:
1/ CTS_HILO is managed by HILO:

  • When CTS_HILO is on active level (low electrical level), that means that HOST (your uC) can send.
  • If CTS_HILO is on inactive level (high electrical level), that means that HOST must stop sending.

2/ RTS_HILO is managed by the HOST:

  • If RTS_HILO is set to the active level (low electrical level), HILO can send.
  • If RTS_HILO is set to the inactive level (high electrical level), that means that HILO must stop sending.