Dacu for the Diva SOM

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Revision as of 14:55, 17 May 2013 by DevWikiAdmin (talk | contribs) (Introduction)

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Info Box
Dacu-top-view.png Applies to Dacu
Diva-am335x-overview.png Applies to Diva

Introduction[edit | edit source]

When used in combinaton with Diva SOM, DACU requires the use of DivaEVB-Lite acting as adaptation board. The overall system looks like the following picture and it is composed by

  • Diva SOM
  • DivaEVB-Lite
  • Dacu carrier board.


In order to make DACU compatible with this configuration, some additional wired connections are required, as detailed in the schematics. Following sections explains in more detail these issues.

Block diagram[edit | edit source]

The following figure shows the system block diagram:

Dacu-diva-block diagram.png

Power supply[edit | edit source]

This is the power-up sequence of the whole system (it matches Diva recommended power-up sequence):

  1. power supply or wall adapter connected to DACU's JP2 is turned on
  2. DACU's U15 DC/DC PSU is turned on; since the output of this DC/DC is connected to DivaEVB-Lite's VREG rail, Diva SOM is powered
  3. Diva performs its own power-on sequence
  4. DivaEVB-Lite's U4 linear regulator is enabled by Diva
  5. DivaEVB-Lite's 3.3V rail raises; since this rail is connected to DACU's ENA_3.3V, DACU's U16 DC/DC PSU is enabled and DACU's circuitry interfacing processor's I/O is powered

DACU's USB host port[edit | edit source]

DACU's USB host port power is controlled by Micrel MIC2026 Dual-Channel Power Distribution Switch (U7). B channel of this swith is associated to USB host port. In order to control this channel, Diva's USB1_DRVVBUS and VUSB_VBUS1 signals are connected to ENB and FLGB pads respectively.