RS-232 defines the levels, the different signals, and the physical connectors. However, baud rate, parity, stop bits, and the like are at a "level" above RS-232, and so outside its scope.
Egregious rent seeking grifters at TIA demanding $165 per half-assed scanned copy[1] of a near 3-decade-old document that they couldn't even be bothered to properly OCR, and somehow IBM gets to shoulder the blame for the interoperability clusterfuck that ensued as everyone and their mother was profiting off their innovation?
Oh, come off it.
[1] https://store.accuristech.com/tia/standards/tia-tia-232-f?pr...
The general public at large already pays huge amounts of money to various standardization organizations, be it ISO, IEC, DIN, UL, whatever. The resulting works should be public domain, similar to patents.
And remember, with whatever it’s called, in addition to sending characters of various bit lengths, you can send a “break”.
UARTs are called universal because they can be configured to work with "any" asynchronous serial protocol (within their bounds), which usually means
- 1 start bit
- 5-9 data bits
- even or odd parity
- 1-2 or sometimes 3 stop bits
per frame. Hardware UARTs also typically oversample 16x, which is why simple software UARTs are often somewhat glitchy.
Split each byte in 4-bit nibbles and used the remaining data bit for not-quite-in-band-signalling.
The Wikipedia article [0] calls this category “asynchronous start-stop signaling” but has no source.
I guess the best term is “UART protocol”, despite the limited size of the “universe”, since it’s really just a de facto convention established by decades of chips called “UARTs”.
[0] https://en.wikipedia.org/wiki/Asynchronous_serial_communicat...