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using UART to communicate between fpga and pc



i am using Altera Stratix® V GX FPGA (5SGXEA7N2F45C2) and i have designed the UART program to communicate between the fpga and my pc. and the compilation was a success, but the problem is when i try to assign the UART tx, rx  pins. i can't find any in the data sheet. so i need to know is there any other way or do i need to change the bord?

Thank you

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3 Replies
Valued Contributor II

Is this your own custom board, or an off the shelf development board?

If it is your own board, you need to have wired up some pins as UART RX and TX to external RS232 transceivers (or LVTTL if you are directly using LVTTL levels).

FPGAs typically will have no predefined pins for such generic internal logic. It is up to you to assign.


Hi ak6dn,

Thank you for you are reply. My bored is not my own custom made it was manufactured by TERASIC company. i have one more board that is ARRIA V V GX 5AGXFB3H4F35C4N, which was released by Intel i self.

i went through both the data sheets but i cannot find the UART RX and TX to external RS232 transceivers (or LVTTL).

Valued Contributor II

Well, looks like your are out of luck for RS232.

It appears you have the DE5-NET TerASIC board (the only one TerASIC has that uses the StratixV part you refer to) and that board is basically a PCIE add-in board with SFP+ module support for networking.

There is no RS232 support on board. There is no generic I/O pin availability via a header.

There is only an RJ45 connector present that has an RS422 transceiver. Using that is your only option.

That board is basically designed to act as an add-in accelerator to a computer via the PCIE bus with high speed network support via SFP+ module connectors. Not a good choice for a generic development board.

So you need to either rewrite your code to use RS422 instead of RS232, or else find another board.