Location of "nUSB_PWR" signal ?

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1

I am designing an expansion board for the XM, I found several errors
in the manual "BeagleBoard-xM System Reference Manual Revision A3".
The external connector tables are miss-labeled in some places (.ex
table 26 is marked as P13 and should be P17.) In section "8.3.3 DC
Source Control" the signal "nUSB_POWER" is referenced. This signal
cannot be found in any of the connector tables. The schematic
indicates it's located on LCD expansion connector P13 pin 12. However,
the description in table 25 indicates this pin is not connected.
Figure 51 shows a signal "nUSB_DC_EN" on pin 25 of the main expansion
header. However, this signal is labeled "REGEN" in table 25 and on the
schematic. 1) Does anyone know if these discrepancies have been fixed
in any documentation? 2) Can I believe the schematic for P13 pin 12
being "nUSB_POWER"? 3) Does "nUSB_DC_EN" exist on the expansion
connector pin 25 and is its function the same as "nUSB_POWER"?

                  Thanks,
                   Tom

2

Feel free to send me any errors you find and I will get them corrected. You can also try looking at the latest version of the SRM as some things have been fixed in the latest version.

The nUSB_PWR signal is on the schematic. It goes to pin 12 of P13. Always follow the schematic if you have any doubts. yes, you can believe the schematic as it pertains to the board you are working with. The different revisions are different in some areas from one revision to the next. The SRM is description of the schematic.

PIN 25 is the REGEN signal which comes from the PMIC. It is for power sequencing purposes to tell external power regulators on expansion cards when to turn on. It is not the same as the nUSB_PWR signal, which just indicates that the DC power supply is not plugged in and therefore the power is coming from the USB port.

Gerald