[Discuss-gnuradio] Daughterboard clocking on USRP2

[John Orlando]

Hi all,
Just looking through the WBX daughterboard code in the latest git repo
for adding support for the USRP2 (which can be found at
usrp2/firmware/lib/).  I noticed that in adf4350.c, there is a #define
for INPUT_REF_FREQ that is defined as 50e6 (50 MHz), which is then
used in all of the follow-on calculations for determining register
settings.  I had thought that the USRP2 only provided a 100 MHz ref
clock for use by the daughterboards on the clock_rx_p line, but I must
be missing a divide by 2 some place.  Can anyone confirm A) if the WBX
runs off of 50 or 100 MHz, and B) if it is 50 MHz, how the clk div 2
occurs on the USRP2?

Thanks much...

-- 
Regards,
John Orlando
CEO/System Architect
Epiq Solutions
www.epiq-solutions.com