2 Feb
2025
2 Feb
'25
11:07 p.m.
On Sun, 2 Feb 2025, Chuck Guzis via cctalk wrote:
Sure, I just gave it as another example that you can wire a UART that
uses TTL or other standard digital circuit signalling to different line
drivers ("phys"). It all boils down to the application.
Maciej
I forgot to
mention: MIDI has been another notable example where you want
to wire a UART to another kind of line driver. I also have a computer
where one of USARTs is multiplexed (software-configurable) between an
RS-232 line driver with an external DE-9 connector (with pins multiplexed
between synchronous-mode TxC/RxC clock lines and asynchronous-mode CTS/DSR
inputs respectively) and an AC'97 audio codec (the codec uses the USART's
synchronous mode with internal clocking). This one obviously also uses
regular voltage levels to talk to the AC'97 device.
Except that MIDI is a current-driven interface, not voltage like RS232.
5 ma currentloop, if memory serves.Voltage is secondary.