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Re: [usb] USB1.1 Core Address Assignment Failing. Debuggingsuggestions?



On Tue, 2003-06-03 at 20:02, Evan Jones wrote:
> I'm a little embarrassed now. Just 1 day after posting my original 
> request for help, we got the thing working!
> 
> On Tuesday, Jun 3, 2003, at 05:05 Canada/Eastern, Rudolf Usselmann 
> wrote:
> > Function address 0 seems to be strange. Never have seen that ...
> 
> Well, the bizarre errors that we were seeing were caused by some 
> strange interactions between the
> 
> We eventually realized the problem because we were reading the "state" 
> variable inside usb_ctrl.v, and it never changed. It turns out that 
> when we examined the compile messages, it was being detected as being 
> stuck at ground, and optimized away. The problem was that when we were 
> intitially compiling the core for our Altera APEX 20K200E, the Quartus 
> II software reported it as not meeting the timing constraints. Then we 
> found the "VENDOR_ALTERA" define (I can't remember which file exactly 
> now) and after setting that, it compiled MUCH faster (because it was 
> optimizing away a bunch of critical things). After all our furious 
> debugging, we started with the USB1.1 function controller source from 
> scratch and it compiled fast enough the first time, and worked the 
> first time!

This is great news ! I'm glad it worked out !

> The important question now is, is that "VENDOR_ALTERA" setting  
> supposed to work on the APEX 20K200E chip? Because it doesn't appear to.

Ahh, this is probably in the "generic_memories.v" file. It's
actually something I did not write, but if I remember correctly
it supposed to allow you to select the appropriate, optimized
built in memories for several FPGAs (Xilinx & Altera) and also
for a few ASIC libraries. It might be that the selection mechanism
is broken or that Quartus is broken (more likely in my opinion :*).

> Thank you for your assistance, and for the USB1.1 core. Once we get the 
> system working more thoroughly, we will be submitting some 
> documentation for the core.
> 
> Evan Jones

Cheers !
rudi               
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