[Arm-netbook] [EOMA68-A20] SATA testing

luke.leighton luke.leighton at gmail.com
Thu Sep 5 00:17:30 BST 2013


On Thu, Sep 5, 2013 at 12:11 AM, joem <joem at martindale-electric.co.uk> wrote:

> you can balance the tracks by cutting both tracks and inserting the 0.1R resistor

 i meant "are they the right length" - the answer's that the TX lines
are 7ps out but the spec says that up to 30ps is ok.

> in each track and connect both resistors with scope probes to further balance it.
> (A bit excessive me thinks for the kind of results you can extract from it.)

 well... i'm thinking perhaps the capacitors should be replaced with
0R resistors temporarily (so that no board-level revisions are needed)
and then the capacitors put onto the external I/O board, as near as
possible to the SATA connector.

 i think... i think i think.... i will go via maplin's tomorrow and
get some 103 capacitors.  i've already removed one of the SATA
connectors from one of the MEBs.

l.



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