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Is it valid by the protocol of a FFUART 16550 to configure one side (Machine A) to 155200 baud rate and the other side (Machine B) to 1200? Should I expect the connection to work flawlessly in the lower rate?

I would really appreciate pointers to knowledge sources on the web stating possible configurations in a user friendly way.

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When you say "one side" and the "other side" do you mean the transmit and receive side on the client or do you mean setting one end point (your client for example) to one speed and the other end point (the external serial device) to another? – Helvick Jan 31 '10 at 16:11
@Helvick: it's practically the same: UART always transmits at it's own frequency, so other side must be able to receive on others' freq. – whitequark Jan 31 '10 at 16:18
up vote 1 down vote accepted

The UART cannot work with different baud rates on two sides.

16550 UART always tramsmits bits with it's own frequency, and is expecting to receive bits (after detecting the start bit) at it's own frequency too. The transmit/receive process is nicely described on Wikipedia, and this is an example of datasheet for 16550 compatible UART from National Semiconductor.

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Thanks, I'll read through. Can you update the link for the datasheet? – Shaihi Jan 31 '10 at 16:41
Fixed the link. – whitequark Jan 31 '10 at 16:58

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