By specifying rts=pin(x) and/or cts=Pin(x) in the constructor. The pad
numbers for the UART pins are fix in this case: TX must be at pad 0, RX at
pad 1, RTS at pad 2 and CTS at pad 3.
repr(uart) shows the pin names for rts and cts, if set. In case of a RX
overflow, the rx interrupt will be disabled instead of just discarding the
data. That allows RTS to act.
If RTS is inactive, still 2 bytes can be buffered in the FIFO.
Signed-off-by: robert-hh <robert@hammelrath.com>
robert-hh