interfacing Altera Cyclone 3 FPGA to a peripheral using UART

[Altera_Forum]

Hi everybody, 

i'm working in my 1st project in FPGA Altera Cyclone 3 (EP3C25) and i have to connect a peripheral that have only an UART interface to my FPGA.  which interface of the FPGA board i have to use? and how to connect it? so since i'm beginner, i asked if anyone can help me. thanks!!

[Altera_Forum]

I dare say you need a UART interface on FPGA. 

How to connect it depends on what are you implementing inside FPGA. Talking strictly about connections, UART usually requires only a tx and a rx signal and possibly a RS232 transceiver.

[Altera_Forum]

--- Quote Start ---  I dare say you need a UART interface on FPGA. How to connect it depends on what are you implementing inside FPGA. Talking strictly about connections, UART usually requires only a tx and a rx signal and possibly a RS232 transceiver.  --- Quote End ---     thanks cris i have to connect a wireless module (have only an UART interface for serial communication) to the FPGA . But i don't know how to implement it on the FPGA since i didn't find already a UART interface on FPGA. About connections i know that a UART connection need only a tx and rx but as i say after reading datasheet it seem there's no interface to connect directly the wireless module

[Altera_Forum]

How are you supposed to drive the UART and the required protocol to interface the wireless module? 

Do you plan to implement a Nios processor? In this case you need to instantiate the uart core in sopc builder and then you only need to write the software driver. Otherwise you have to code everything in raw HDL, but this is definitely not a task for a beginner.

[Altera_Forum]

--- Quote Start ---  How are you supposed to drive the UART and the required protocol to interface the wireless module? Do you plan to implement a Nios processor? In this case you need to instantiate the uart core in sopc builder and then you only need to write the software driver. Otherwise you have to code everything in raw HDL, but this is definitely not a task for a beginner.  --- Quote End ---    i will promming it in VHDL and i know that's not easy at all. for the moment the problem is not for the programming side but strictly electronic : how can i ensure the connection between the wireless module and FPGA? may i create a new interface or can i use the HSMC Connector to realise a UART connection?

[Altera_Forum]

From what you said I guess you are targeting a CIII starter board: then you can definitely use the HSMC connector. 

Any internal signals implemented in fpga logic can be routed to any fpga I/O pin: so you only need a pcb trace going from fpga pin to a board connector pin. As I remarked before, you possibly need a buffer (TTL or RS232) to interface the wireless module: read the module datasheet and find out if those uart signaling levels are compatible with fpga I/O ports, which are basically LVTTL. Also check if the wireless module uart requires handshake signals (rts / cts) besides tx and rx: in this case you'll need 4 lines for the interface, 2 inputs and 2 outputs.

[Altera_Forum]

--- Quote Start ---  From what you said I guess you are targeting a CIII starter board: then you can definitely use the HSMC connector. Any internal signals implemented in fpga logic can be routed to any fpga I/O pin: so you only need a pcb trace going from fpga pin to a board connector pin. As I remarked before, you possibly need a buffer (TTL or RS232) to interface the wireless module: read the module datasheet and find out if those uart signaling levels are compatible with fpga I/O ports, which are basically LVTTL. Also check if the wireless module uart requires handshake signals (rts / cts) besides tx and rx: in this case you'll need 4 lines for the interface, 2 inputs and 2 outputs.  --- Quote End ---    thanks a lot cris that's exactly what i mean : i have to use the HSMC connector. the signaling levels are compatible and for wireless module uart is composed from 1 tx and 1 rx so it will be directly connected to the HSMC.