Re: [Discuss-gnuradio] differences between USRP2 rev 3 and rev 4 boards

[Matt Ettus]

On 10/12/2010 02:22 PM, Steve Mcmahon wrote:
> I am wondering what are the differences between the USRP2 rev 3 board
> and the rev 4 board?
>
> I have one of each (one I ordered maybe a year ago and one I ordered
> this past summer), and I don't see any differences on the board
> itself. I understand that the versions of the FPGA image and the
> firmware that shipped on the SD card from the factory would be
> different, since over a year of time elapsed between my purchasing
> the two boards. But what else is different? I can't find a changelog
> for the USRP2 boards anywhere.

Some clocks were reorganized for layout reasons and the PPS input 
circuit was modified to have a more consistent delay.  The same FPGA 
image works for both.

Matt