Nexys Video

[Bilal29]

I recently purchased nexys video board and after powering ON in default conditioned, i noticed FPGA temperature is increasing (Temperature is displayed on Screen). When it reaches 47 degree c, i disconnected its power. Is this a problem or it is fine ?

Secondly, by default which program is loaded in it ? and by default what i can check without changing code. 

[zygot]

@Bilal29

When you power up your board it is running an application from flash. What you are looking at is the FPGA internal temperature. 47 degrees is fine and if the DDR is running it will go higher. The DDR, when running,  adds quite a bit of thermal energy to the board's copper planes which helps increase the internal temperature of most components on the board. You can move JP4 to the middle 2 pins to prevent power-on configuration from FLASH. The board should not be warm to the touch. Unfortunately, there's no application to run the LCD display and tell you what the FPGA temperature is. An essential tool for the FPGA development lab (especially testing new FPGA based hardware) is an IR temperature reader. You should never touch components on an FPGA board unless you are properly connected to  ground through a ground strap to prevent static discharge. This is deadly to your board.

You are right to be concerned about excessive internal FPGA temperatures, which is why the Series 7 devices have the ability to monitor it. Xilinx provides information on normal operating conditions in its data sheet.

I highly recommend that all applications for Series 7 devices include monitoring of internal temperatures. It would be neat, and instructive,  if Digilent provided a way to look at XADC internal measurements with and without external components operating.

[jpeyron]

Hi @Bilal29,

The FPGA on the Nexys Video is the XC7A200T-1SBG484C. The C means the it is commercial grade for temperature. The  commercial operational temperature range is 0 to 85 °C.  I believe the Nexys Video GPIO demo here is what is loaded into the flash.  The Wiki describes the components being used.

thank you,

Jon

[Bilal29]

By default which program is loaded from flash. If DDR is running then what will be the maximum temperature it will show on display ?

Is there any UCF file of board. Only XDC file is available.

[Bilal29]

hi, jpeyron

It seems that GPIO demo is loaded. I was little worried when i saw temperature increasing. so i just powered off to avoid further damage. But i seems fine as per suggestion.

[zygot]

18 minutes ago, jpeyron said:

The  commercial operational temperature range is 0 to 85 °C.

This refers to the environmental operating temperature limits. Internal temperature will be higher. What counts is the maximum internal temperature if you're worried about damaging your device. Things like delay and switching are temperature dependent and applications that work when the substrate temperature is 40 degrees C might not work at the extremes but I doubt that you'll ever have to worry about it.

 

17 minutes ago, Bilal29 said:

Is there any UCF file of board.

I am not aware of Digilent providing an ISE compatible .ucf file. It might be time consuming ( mostly to check for errors ) but not too hard to create a pin location .ucf constraints file based on the xdc one. The syntax is not completely different. I've done it for a few Digilent boards on a subset of pins. Be aware that ISE doesn't support all of the current variants of Artix and Kintex devices.

[jpeyron]

Hi @Bilal29,

The Nexys Video comes with a heat sink on the board which helps dissipate some of the heat. If you are still concerned about thermal damage you can also use a fan. Looking at this AR the Nexys Video should work with  ISE. We did not create ISE compatible materials for the Nexys Video.  The Nexys 4 and Nexys 4 DDR have xdc's and ucf files. I would suggest looking at these as a reference if you are going to make a ucf file for the Nexys Video.

thank you,

Jon

 

 

 

 

 

[zygot]

Xilinx tools definitely take [expected]  internal operating temperatures into account when calculating timing analyses. Their tools don't make this obvious. For anyone wanting to do a lot of FPGA design I suggest downloading a free version of Quartus from Intel. Intel (ALTERA) provides a much better reporting of expected timing due to [expected] temperature. Reading Quartus reports for an FPGA board demo will be at least instuctive to those who's experience is limited to Xilinx tools. The tools, of course, don't have a way to know how a particular board will contribute to the difference between [exected] and actual junction temperatures. I can tell you that it isn't necessarily the same throughout the entire device depending on what IO bank is driving a particular external device.

I you are using your Nexys Video in the lab without driving a lot of outputs on all of the PMODs and FMC connector you (probably) don't have to worry about temperature. If you are using the FMC connector and all of the boards interfaces that might not be so.

The rational for monitoring internal device temperatures becomes more important if you are trying to test new hardware interfaces that might be abusing outputs. {edited} If you are driving a few outputs into ground with maximum current constraints the XADC won't be of much use as by the time you see a reading you probably have damaged the device.

It's not my intention to spread FUD, just useful information. Your question is one that I've not seen before and is a good one.