At 2004-06-15 00:48, Roger Morella wrote: >I'm looking for a microcontroller with 2 onboard serial UARTS so I can >implement add a dual RS485 function to am existing design. A parallel >slave port to integrate to my host circuit would also be useful. A 44 >pin PLCC form factor would also help. Does anyone out there have any >idea devices that they have had positive results with?
You could also consider implementing some software based UART's when your maximum bitrate is not too high. The 6811 for example has nice counters/timers with which it's quite easy to do. Output isn't really a problem, but input might be: First program a counter/timer to notice the beginning of the startbit. Then check again half a bit time later if the line is still in the 0-state. After that you can sample again after every bit-time (so half way during each bit-period), but it's better to over- sample and read the level three times during each bit and go for the 2 or more out of 3, to exclude spikes. Another way to implement more UARTS is by connecting special chips to a serial bit-shift port like the SPI-interface on the 6811. See also: http://www.chipdir.nl/uart.htm Greetings, Jaap -- Chip Directory -- http://www.chipdir.biz/ -- http://www.chipdir.info/ -- http://www.chipdir.net/ -- http://www.chipdir.nl/ -- http://www.chipdir.org/ -- And about 30 other mirror sites world-wide. -- -- To subscribe to a free 'chip issues, questions and answers' -- mailing list, send a message to [EMAIL PROTECTED] with -- in the body 'subscribe chipdir-L'. About 500 experts are -- willing to think with you about electronics problems etc. -- Author: Jaap van Ganswijk INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
