Atmel Evaluation Kit AT91SAM9G20-EK AT91SAM9G20-EK Fiche De Données

6413C–ATARM–18-Feb-09

There is a silkscreen reversion on the board, for the selection of the VDDBU source:

„

On J10 position 1-2, the marking should be ‘BB’ for Battery Backup instead of ‘1.0V’

„

On J10 position 2-3, the marking should be ‘1.0V’ instead of ‘BB’.

This erratum is not applicable for AT91SAM9G20-EK Rev. C and later versions.

For many reasons at the manufacturing level, Atmel does not specify any crystal references at the board
design stage.

Because of that, the user can find an inconsistency in the value of the used capacitance of the
18.432 MHz crystal on each pin (C23, C24), and the nominal load capacitance of the crystal. 

As a reminder, here is the way to select these values.The electrical parameter allows you to fit the right
values provided by the crystal manufacturer - and not by Atmel. They are called "Load Capacitance" of
the crystal. You have to take stray capacitances (package, socket, trace) into account in order to be
close enough to the equivalent nominal Load Capacitance.

With the on-board HCM49-18.432MABJT crystal reference, 10 pF capacitances have been fitted on the
18.432 MHz crystal for a nominal 27 pF load capacitance.

On the board, Slot J13 is incorrectly marked with a “bootable” mention (solder side). This should be
applied to J35 instead. However, the schematic entitled ” Memory” attached to this User Guide, in 

 does represent the correct location and marking.