SATA - is reduced rate signalling possible?

  • Thread starter Thread starter RM
  • Start date Start date
R

RM

Is it possible to operate a SATA drive at reduced signaling rate (i.e., less
than the nominal 1.5Mb/s)? It appears not all implementations recover the
embedded clock for sync - some may use a local clock (presumably at
1.5Mb/s), and use the embedded clock to resync. Yet there's just enough
weasel wording in the actual spec to make me believe that there was an
intention to allow reduced rate signaling.

Does anyone have any experience with this?

Thanks,
RM
 
RM said:
Is it possible to operate a SATA drive at reduced signaling rate (i.e., less
than the nominal 1.5Mb/s)? It appears not all implementations recover the
embedded clock for sync - some may use a local clock (presumably at
1.5Mb/s), and use the embedded clock to resync. Yet there's just enough
weasel wording in the actual spec to make me believe that there was an
intention to allow reduced rate signaling.

Does anyone have any experience with this?

Thanks,
RM
Click to expand...

Which wording makes you believe that?

All SATA-1 devices work at 1.5Gbit/sec serial stream rate.
 
Previously RM said:
Is it possible to operate a SATA drive at reduced signaling rate (i.e., less
than the nominal 1.5Mb/s)? It appears not all implementations recover the
embedded clock for sync - some may use a local clock (presumably at
1.5Mb/s), and use the embedded clock to resync. Yet there's just enough
weasel wording in the actual spec to make me believe that there was an
intention to allow reduced rate signaling.
Click to expand...
Does anyone have any experience with this?
Click to expand...

Since layer1 is syncronous, reduced rates would probably
need changed hardware, i.e. be impossible with existing
devices.

Arno
 
Peter said:
Which wording makes you believe that?
Click to expand...
Actually, the more I re-read, the clearer it is that 1.5Gb/s is basic to
Gen1 signalling. I guess it was just wishfull thinking. That high a rate is
going dictate an external PHY. So much for being creative.
All SATA-1 devices work at 1.5Gbit/sec serial stream rate.
Click to expand...
Of course, I meant 1.5Gb/s. Thanks for the response.
 
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