Module usart 

Asynchronous serial (USART), blocking and non-blocking.

Word width is a typestate: a Usart<.., Byte> moves u8 values and is what new builds, while new_word gives a Usart<.., Word> for raw 9-bit frames carrying u16.

let tx = parts.pa9.into_alternate::<1>();
let rx = parts.pa10.into_alternate::<1>();
let mut serial = Usart::new(&mut rcu, dp.usart0, tx, rx, UsartConfig::default());
serial.write_byte(b'x');

Which pins are valid depends on the chip variant: on x6/x8 PA2/PA3 reach USART1, not USART0.

A receiver just built takes the first frame apart wrongly unless the line has been idle for a frame beforehand, and with frames arriving back to back the damage carries through the whole burst. Against a peer that comes up at the same time this never shows: raising TEN sends an idle frame. It bites when the peer is already transmitting — then the line has to be given that idle, by waiting a frame time before the traffic starts.

Modules

baud

Named constants for the standard bit rates.

Structs

Byte

Word-width marker: 8-bit words (Usart::write_byte, Usart::read_byte), optionally with parity.

Usart

A configured USART, owning the peripheral and both pins.

UsartConfig

Configuration for Usart::new.

UsartConfig9

Configuration for Usart::new_word.

Word

Word-width marker: raw 9-bit words (Usart::write_word, Usart::read_word), no parity possible.

Enums

Error

A line error the receiver reported for one frame.

Event

A USART event that can raise an interrupt.

FrameFormat

Word length and parity, as a single setting.

Oversampling

How many times each bit is sampled.

Traits

BusClocks

Supplies the clock frequency feeding a given USART.

RxPin

Marks a pin usable as RX for USART, in the right alternate function.

TxPin

Marks a pin usable as TX for USART, in the right alternate function.