[casper] KatADC est_brd_clk

[Gary, Dale E.]

Hi All,

We are bringing multiple ROACH2 boards online, each equipped with two
KatADC boards.  To my surprise, 3 of our 8 ROACH2s show a 401 MHz FPGA
clock rate, as returned from the Python KATCP est_brd_clk() function, when
supplying an 800 MHz clock to the ADCs.  The others show the correct value
of 200 MHz.  There is a difference in ROACH2 LED status lights on these
boards as well (LED #1 is out on the misbehaving boards).  Does anyone know
what might cause this, or have a suggestion of what to try?  KatADC
problem, or ROACH problem, or something else?

Thanks,
Dale