On Tuesday 19 October 2010, 16:29:48 Grant Edwards wrote: > On 2010-10-19, Claudio Scordino <claudio@xxxxxxxxxxxxxxx> wrote: > > +2. HARDWARE-RELATED CONSIDERATIONS > > + > > + Some CPUs (e.g., Atmel AT91) contain a transceiver capable of working > > both + as RS232 and RS485. > > Pardon my curiosity, but I've looked at a few AT91 parts, and I've > never seen on with an internal transceiver -- nor does Google seem > able to find any. > > Frankly, I'd be pretty surprised, since it would be very difficult > (fab-wise), to build a mircoprocessor with I/O cells capable of > withstanding the voltage levels specified in RS232. > > Can you specify to which parts you're referring? I doubt the AT91 do have an internal transceiver but it has a dedicated pin feature (RTS or CTS or something) which can be used to switch between RS232 and RS485 by setting a bit in the USART provided the pin is connected properly. Regards, Alexander -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
