FW: RK05 question

From: Paul Koning <pkoning_at_equallogic.com>
Date: Tue Jul 13 09:37:48 2004

>>>>> "Gooijen" == Gooijen H <Gooijen> writes:

 Gooijen> Isn't the track index pulse == the one pulse that is fed to
 Gooijen> the PLL phase comparator? That pulse is used to synchronize
 Gooijen> the oscillator that must run at 12 (or 16) times the
 Gooijen> frequency between 2 sector pulses to generate the (missing)
 Gooijen> sector pulses .... or am I mistaken here?

No, what I meant is to derive the 16x sector pulses from the 12x
sector pulses, keeping the track pulse as it is. But either would be
possible.

The track slot is close to the first sector slot (it's not halfway
between sectors). What I don't remember is how close, or whether the
sector slot spacing around the track index is the same as elsewhere,
or different. That would affect the PLL design a lot...

To do this right would require measuring the angular positions of all
the slots on a 12 sector and 16 sector pack, to see just what the
pattern looks like and how to transform one to the other.

        paul
Received on Tue Jul 13 2004 - 09:37:48 BST