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New Contributor I
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multiple drivers due to conflicting nodes

I cannot find any documentation on the "multiple drivers due to conflicting nodes" error.

Which handbook/guide would this be documented inside?

I'm using Quartus Prime Lite Edition Version 20.1.0 Build 711 06/05/2020

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Moderator
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Usually when you right click the error message, it will show you the details in a link.


Can you copy and paste the full error message here?


this might due to when you are assigning the same signal on 2 different edges. Doing something like:


always @(posedge clk)

foo<=value


always @(posedge other_signal)

foo<=other_value


will quite likely result in such an error, because foo is a single flip-flop and it can be clocked from one source. You could do some additional logic that will take clk and other_signal and generate single write strobe out of those two, but then you will quite possibly run into warnings concerning usage of general routing resources as clock signals. If you add something like this:


Code: [Select]

always @ (a, b, c)

if(a)

foo=b;

else

foo=c;

(this should synthesize to a mux)


then you will most definitely get that error, since mux will result in non-registered value, and the clocked part will produce a registered value.


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New Contributor I
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Hi @KennyT_Intel . Sure, the error I get is (using right-click and Copy):

Error (13076): The node "VGAController:vgaController|dataH" has multiple drivers due to the conflicting nodes "dataBus[8]" and "SDRAMController8Bit:sdramController|ioData[8]"

I'll attach my project - probably easier - it also relates to all of the many questions I had in my previous post too.

SystemVerilogTest1.sv is my top level file. There's a lot of unfinished rubbish in it's state machine but hopefully it will help. I really do need to move to non-blocking assignments too but.. I haven't.. yet.

 

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