Re: [Discuss-gnuradio] Routing and Placing and Clock for FPGA !

[Brian Padalino]

On Dec 4, 2007 8:30 PM, Ronald Jetli <address@hidden> wrote:
> Hi,
>
> Needed to confirm a few things:
>
> 1) Is the global clock frequency for USRP 64Mhz ?

Yes.  It's a fully synchronous design with FIFO boundaries where it
talks to the FX2 chip which runs at a different clock speed I believe.

> 2) Do we use this global clock frequency for FPGA on the USRP and not the
> FPGA's clock ? Because, I think the EP1C12Q240C8 FPGA runs at much higher
> clock speeds. So, we are using
> global clock to achieve synchronisation.

When the FPGA is routed, there isn't much more slack above the 64MHz
for Fmax (or so I thought).  I am not sure what you mean when you
state the part runs much higher clock speeds.

What do you mean by synchronization?  It is a little vague and ambiguous.

> 3) Also, is the automatic route and place tools provided by the Quartus
> software, being used for FPGA  ? While compiling, I see that automatic place
> and routing is happening. But still wanted to confirm if that is true or is
> it being manually configured (for already compiled rbfs) to achieve higher
> efficiency.

Quartus does all the work when translating the RTL into a programming file.

Brian