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[time-freq] REFLOCK II questions

Christopher Hoover ch at murgatroid.com
Sat Jan 14 03:45:42 UTC 2006


Hi folks,
 
I put a REFLOCK II kit together the other evening.   Nice design.  
 
Several suggestions for the next revision if there is one: I would have like
to have seen switches (there are nice low profile SMT DIP switches) for R
and N and the use of resistor packs for the pull ups.  Ditto for PD; jumpers
would be good here (2mm?).  Testpoints for the divided outputs would be
valuable.
 
Anyhow, I'm having a bit of trouble with the jumpers.

I programmed the board with r2_flex_01 from r2_conf_nov05_02.  The MD5 hash
of the pof is f91b4faaafd742cba4851a6c8ae28e17.
 
Both ref and fin are fed by 10 MHz.   ref is from an extremely stable source
(GPS-disciplined Rb oscillator).   fin is from an HP 10811A.
 
Signals to the CPLD (pins 89 and 91) look good and are at precisely 10 MHz
and ~10 MHz.
 
I've got R set to (00 0)000.   I've got N set to 0000 0000 0001.
 
The divided signals on pins 73 and 74 are 2.5 MHz (fout) and 50 KHz (rout).
That's division by 4 and 200.
 
According to the documentation, I was expecting division by 100 (R=000) and
division by 1 (N=0..01).
 
A little help?
 
ciao,
-- Christopher.
 
p.s where is the source for the pof files?  is it vhdl or verilog or
something else?
 
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