FMC pins for peripheral adc

[liuz3]

Hello everyone. I have just recently started using FPGAs and I really need some help. The current device I am using is Virtex6 ML605.

I was given a task of making a simple low pass filter using fpga and after completing the VHDL code for it and testing in ISIM I need to move to analog interfacing.

After reading the user manual and some related posts from the forum I came up with 2 answers.

1 is picking out a FMC card with ADC and DAC. This option is too expensive for me right now.

2 is directly connect a cheap ADC IC such as mcp3002 to FMC I/O as I couldn't find any GPIO pins from user manual. I am not sure if this option will work.

If possible please give me some guidance. My last embedded experience was making a simple power consumption monitor using raspberry pi and Arduino. 

Thank you

Sincerely

[gnarahar]

@liuz3 directly connect a cheap ADC IC such as mcp3002 to FMC I/O as I couldn't find any GPIO pins from user manual

How do you plan to connect the ADC pins to the FMC IO on ML605? 

[liuz3]

Thank you for responding.

I was thinking of putting the ADC on a side breadboard and connect the pins to the LPC IO using wires. 

For example the data_in go to LA02_P (H7 on J63) and data_out go to  LA03_P (G9 on J63) as single ended user defined signal.

Is this acceptable? I was using some cheaper FPGA before this and there were GPIOs around the board so it was more clear to me of what to do, but when I switched to ML605 I am afraid that FMC ports are strictly for FMC cards and false use will damage the FPGA. 

Thank you

[gnarahar]

@liuz3 I am more looking at how you plan to solder or connect a wire to the LPC pins on ML605? The LPC pins are on the LPC connector and not easy to connect/solder since the LPC connector is BGA kind of connector. 

[liuz3]

I see then I would assume even If I were to attempt to plug in the wire into FMC port it would be lose and have problem with contact.

Thank you for the heads up.

I am trying to find a solution by google and reading the instruction manual. But has not found answers yet.

Right now another possibility of solution I can think of is to remove the LCD and use its GPIO to interface with peripheral ICs.

But still I really want to hear opinion from people that have more experience then me.

May I ask what is the normal way of connection peripheral ICs to FPGA? 

[gnarahar · Accepted solution]

@liuz3 You can use the LCD header since I believe the ADC you plan to use can operate at 5V. LCD header signals are 5V coming in from a level translator on ML605. 

If you want to use FMC connector, you can use the XM105 FMC Debug card which has headers and you can connect them to your ADC. 

http://www.xilinx.com/products/boards-and-kits/hw-fmc-xm105-g.html?resultsTablePreSelect=documenttype:SeeAll#documentation

[liuz3]

Thanks a lot. That really helped me out.