To make the thing even more confused, in MX31ADS by Freescale PMIC_PWRRDY is connected to GPIO1_1 ...

gtridilbert,
Freescale technical support confirmed your are right:
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The Power Ready signal needs to be connected in the GPIO1_5. The MX31ADS has this signal connected to the GPIO1_5 pin of the CPU. If you follow the GPIO1_5 signal you will see that it comes out of the baseboard's CPLD, if you look at the CPLD's equations you will see the following signal assigned to the GPIO1_5:

assign GPIO1_5 = PWR_RDY;

which comes from the PMIC. It may be confusion about the signal due to a GPIO1_1 signal that appears in the Base Board’s schematic on page 6, just below the PM_PWRRDY signal, but the resistor marked as R379 is not connected in the board so the signal just goes into the CPLD though pin J4.
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HTH

Hello,
PMIC_PWRRDY should be tied to B24 on the MX31 which is GPIO1_5/MCU1_5. This was confirmed with Freescale and changed for the revision 5 schematics in September '06. Schematics revision 6 was released from enineering a few weeks ago. I see neither rev 5 or 6 are on the web yet. I will see if I can speed this process up. I apologize for the delay.

-Kurt

Schematic revision 5 and 6 are now posted to the web. You can download them from this page:
http://www.logicpd.com/auth/downloads/i.MX31/

-Kurt

I haven't found a formal indication of which part number SOM PCB corresponds with each schematic revision. (A LogicPD customer orders a kit, gets a SOM, but doesn't have an easy way of knowing what schematic corresponds to the board.)

Given the dates, it seems likely that:

PN 1006004 -> schematic Rev 4
PN 1006170 -> schematic Rev 5
PN 1006745 -> schematic Rev 6

Is this right?

FYI, for other non-LogicPD readers, the PN in the layer 8 of the PCB. You can just discern it on the bottom side of the board along the long edge of the PCB opposite the SOM connectors.

The "REV A" seems to be a red herring. They are all marked "REV A".

To make this clear:
- The PCB is a unique part and gets a new part number every time the copper changes functionality on the design. This is considered an orderable Part.
- The schematics are a document and are rev'ed, but the revisions do not tie to the PCB part numbering scheme because the PCB is a Part not a Document.
- The BOM/Assembly that is available on the website lists the PCB part number + revision that is tied to the schematic part number + revision for a given assembly part number.

-Kurt