Hardware Description
ARM DUI 0447J
Copyright © 2009-2014, ARM. All rights reserved.
2-11
ID052914
Non-Confidential
2.4
Power
Power to the board is provided by either:
An external 12V power supply
The output goes to the power connector on the back panel. The 12V, 5A,
supply from the back-panel connector goes through an adaptor and
connects to the ATX connector on the motherboard.
An ATX power supply
The output goes to the ATX power connector on the motherboard. The
ATX supply is required for PCI-Express cards.
The voltage regulators on the motherboard supply:
Fixed voltages
There are several voltage regulators on the motherboard that supply fixed
voltages to the motherboard and attached daughterboards.
All daughterboards are supplied with 5V for internal supply generation. If
the daughterboard requires additional supply voltages, a separate power
supply connector must supply them.
VIO
The SMB, SB, and MMB buses operate over the range 0.8-3.3 volts. These
buses must operate at the same voltage that is supplied from the
motherboard. To avoid damage, the daughterboard that has the lowest
operating voltage specification determines the voltage.
PCI-Express connector voltages
The ATX connector directly supplies 12V and 3.3V to cards connected to
the PCI-Express slots.
Note
When power is applied, the system is reconfigured based on the contents of the USBMSD flash
memory. See the
ARM
®
Versatile
™
Express Configuration Technical Reference Manual
.