uart with 21161n

Im implementing an UART for a 21161n DSP as its shown on the EE-191 Analog Devices document.

http://www.analog.com/UploadedFiles/Application_Notes/399447663EE191.pdf

According to the schematic two flag pins can be optionally connected to manage the CTS and RTS control signals.

Could anybody explain me where may I connect them (what FLAGx and FLAGy are?) and whats their utility?

Thanks,
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On Fri, 14 Jul 2006 h...@yahoo.fr wrote:

> Im implementing an UART for a 21161n DSP as its shown on the EE-191 Analog Devices document.
>
> http://www.analog.com/UploadedFiles/Application_Notes/399447663EE191.pdf
>
> According to the schematic two flag pins can be optionally connected to manage the CTS and RTS control signals.
>
> Could anybody explain me where may I connect them (what FLAGx and FLAGy are?) and whats their utility?

Any flag pins will work, so pick the most convienient. CTS is input, RTS
is output. When CTS is low, stop sending data, when CTS is high you can
send. Pull RTS low when you want the other side to stop sending you data.
A search on RS232 protocol will explain it.

Note that "low" and "high" are logic not voltage level. Life can get
really confusing because the full standard is based on +/- 10V signals
and lots of logic translators call -10V = +TTL and +10V = GND. But not
all of them :-) Good luck!

Patience, persistence, truth,
Dr. mike

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