LogicStart MegaWing v1.2 - U1 IC is hotting


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I'm newbie with FPGAs so I found the Mike Field's book and I bought both a Papilio One 500K and a LogicStart MegaWind board as suggested. The first time I plugged the LogicStart MegaWing on the Papilio One, it lighted up all the LEDs on it. Then I followed the book and after some issues I could finally generate a .bit file as described in "Your First Design" chapter. I tried to load it using the Papilio Loader but unexpectedly the program didn't work (the switches didn't light up any LED). 

But the real problem now is that the board began to smell burned. I tried to check it and I realized the ADC U1 IC was hotting!! Although I erased the FPGA with the Papilio Loader, the IC continues becoming very hot in a few seconds.    


I tried to check if there was any shortcircuit between the ADC port pins, but everything seems to be correct. I don't know what else can I check. My Papilio One jumper's settings are USB and 3.3V. 


Any help will be appreciated! 

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That is not normal behavior, every board is put through a test plan when it is manufactured that should catch problems like this. But it sounds like this board must have fallen through the cracks. Please send us an email at support@gadgetfactory.net with a link to this thread and your current shipping address and we will send you out a replacement board.




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It is a pity, but don't worry at all. Yesterday Mike Field suggested me to plug the lower 'Wing C' connector into the 'Wing B' socket and modify accordingly the constraints.ucf file:

# Constraints for Papilio One
NET switch_1     LOC = "P63"     | IOSTANDARD=LVTTL;
NET switch_0     LOC = "P61"     | IOSTANDARD=LVTTL;
NET LED_1         LOC = "P25"     | IOSTANDARD=LVTTL;
NET LED_0         LOC = "P22"     | IOSTANDARD=LVTTL;
Surprisingly now the "switches_led" program is working, but unfortunately the U1 IC is still hotting.
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  • 2 weeks later...

I just remembered that an old  "BPM7003-Papilio-Pro-LogicStart-MegaWing-general.ucf" file had some errors in it - the LEDs and Switches were transposed.


In case anybody else has a problem with the LEDs or switches, just check that the LEDs are on pins P123 through P134:

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Thank you very much for your info Hamster, but I still don't know how you get the relationship between the pins and the LEDs. The pin assignment I have goes only from P2 to P98. There is neither P123 nor P134. 


The UCF file I use has the following pin assignment:

# Main board wing pin [] to FPGA pin Pxx map# -------C-------    -------B-------    -------A-------# [GND] [C00] P91    [GND] [B00] P85    P86 [A15]# [2V5] [C01] P92    [2V5] [B01] P83    P84 [A14]# [3V3] [C02] P94    [3V3] [B02] P78    P79 [A13]# [5V0] [C03] P95    [5V0] [B03] P71    P70 [A12]#       [C04] P98          [B04] P68    P67 [A11] [5V0]#       [C05] P2           [B05] P66    P65 [A10] [3V3]#       [C06] P3           [B06] P63    P62 [A09] [2V5]#       [C07] P4           [B07] P61    P60 [A08] [GND]# [GND] [C08] P5     [GND] [B08] P58    P57 [A07]# [2V5] [C09] P9     [2V5] [B09] P54    P53 [A06]# [3V3] [C10] P10    [3V3] [B10] P41    P40 [A05]# [5V0] [C11] P11    [5V0] [B11] P36    P35 [A04]#       [C12] P12          [B12] P34    P33 [A03] [5V0]#       [C13] P15          [B13] P32    P26 [A02] [3V3]#       [C14] P16          [B14] P25    P23 [A01] [2V5]#       [C15] P17          [B15] P22    P18 [A00] [GND]
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  • 1 month later...

Hi Jack,


finally I've received today a new Papilio One 500K board, but my surprise when I plugged it to the LogicStart MegaWing v1.2. With the default program it started flashing all the LEDs but the U1 IC is still hotting. I guess the problem is on the LogicStart, right?.


Any ideas where the problem could be?.  

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Oh wait, you mean the U1 of the LogicStart MegaWing is getting hot. If that is the chip that is getting hot then the LogicStart MegaWing should have been replaced not the P1 500K... Not sure why the 500K would have been sent out, it was an error. Please send an email to support@gadgetfactory.net so they can send you the correct board.



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