Wanring Message

[Altera_Forum]

Hello: 

 I'm using Quartus 4.1 on a Cyclone device.  I have a FIFO that I built with the LPM Plug In Manager. It's 16 bits wide and 256 locations deep. The output of that FIFO goes to a 16 bit tristate bus module (LPM_BUSTRI) also build with the LPM Plug In Manager.  I'm getting the following warning:  Warning: Port tridata of type lpm_bustri2 and instance inst6 is missing source signal  The compiler didn't warn that it removed any of the other signals in the design.  Did I miss something? What's Best way to track this down?  Thanks George

[Altera_Forum]

assuming that inst6 is the tristate buffer. You don't seem to have a connection to the tristate. Make sure you're fifo isn't being synthesized out. 

 Also if you're just buffering a 16 bit bus then use the primative tri-state and just feed it with the bus (I looks like it takes a single connection but it can be bused)

[Altera_Forum]

I used the RTL viewer and found everything properly connected; for what ever that's eorth. 

I also liike at the resources used and found the FIFO had consumed the proper amoune to internal RAM. So I suspect that everything was OK.   I then did replaced the lpm tristate with the primitive and hte warning message went away!!!! WHY????

[Altera_Forum]

The magic of Quartus hehe. 

 If you can avoid Megawizard functions and use primitive then I recommend doing so (as you just found out).  It's probably some little simple setting that you missed and it threw off the design.