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Implementation 12 RS232/Rs485/RS422 Ports in FPGA

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prabhukaran3

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Hi friends!
Looks so great to see you again... Now I am working with FPGA kits.. I hope FPGAs are almost same as micro controllers except pin configuration flexibility. I want to implement 12 RS232/422/485 ports. At any time I wil change the port configuration settings(All ports as RS-485 or 2 ports RS-232 and 6 Ports in RS-485 mode and remaining is RS-422 mode)..... Setting informations will be given by another micro controller.... Before that I need to ensure.. programmed-compiler support needed)

RS232 voltage levels +/-12V
RS485/RS422 Voltage levels +/-5V


Is it possible? If yes please specify some FPGA ICs(It should be easily
 

barry

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1) FPGAs are NOT THE "SAME AS MICROCONTROLLERS".
2) FPGAs are NOT THE "SAME AS MICROCONTROLLERS".

You need to read something.

FPGAs don't know anything about RS-232/422; those protocols are dependent on what drivers you connect to the FPGA.

You will need to implement the UART functions in the FPGA, either writing your own or using someone else's IP.

And what does "(It should be easily" supposed to mean? It looks like you passed out in the middle of writing your post.
 

hobbyckts

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No dedicated functions will be available on the FPGA. You need to assign each and every function on each pins of the FPGA. FPGA will be same as micro-controller only when you are using all the micro-controller pins as port pins. Otherwise there are more differences.

You dont want to worry about the voltage level of RS232 & RS485/RS422 when you are using Transceiver for same. You just need to control it. In RS485 mode the controlling is little bit critical considering which mode you are going to use either half duplex or full duplex.
 

betwixt

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FPGAs are just a collection of gates you put together yourself to make something useful happen. You build the functionality from basic logic blocks. A microcontroller is already built to do a job, the software you put in it tells it what to do. So the two are nothing like each other.

As far as I know there are no FPGAs or microcontrollers that can handle any negative voltages or voltages as high as 12V. In any case RS485 and RS422 only use positive voltages!

Brian.
 

prabhukaran3

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Hi,
Very thanks for your replies... Can you suggest some useful links for me to start over. Can I find free lancers through Internet? If yes means what should I give as input... First time stepping into FPGA kits... So little bit fear...
 

ads-ee

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Maybe you should start someplace like this (FPGA 4 fun website), which has a lot of basic circuits you can look at and implement in an FPGA. Definitely read the "FPGA Introduction" section.
 

lucbra

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and forget the idea that FPGA's (programmable logic in general) are like MCU's.
 

hobbyckts

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you also need to study about the logics in RS232, RS485 & RS422... for that wikipedia is enough for the understanding
 

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