VULCAN Technical Manual
Power and power management
© 2007 Eurotech Ltd Issue D
39
MFUNC5 pin on PCI1520 device must be configured as GP output and can be used to
put the XR16L2551 in PowerSave mode. RedBoot configures MFUNC5 pin as GP
output. The same pin is used to power down the Ethernet PHY device.
MFUNC5 (PWRSAVE)
UART Operation Status
Ethernet PHY Operation Status
0
Normal operation
Normal operation
1 PowerSave
Power-down
CompactFlash power management
The TPS2210A PC CardBus
power interface switch provides an integrated power-
management solution for the PC card
socket. This device allows the controlled
distribution of 3.3V and 5V to the CompactFlash card slot. The current-limiting and
thermal-protection features eliminate the need for fuses. The switch r
DS(on)
and current-
limit values are set for the peak and average current requirements stated in the PC
card
specification.
Ethernet power management
The Ethernet PHY device (Intel LXT973) incorporates numerous features to maintain
the lowest power possible. The device can be put into a low-power state via Register 0
of LXT973 as well as a near-zero power state with the power-down pin. When in
power-down mode, the device is not capable of receiving or transmitting packets. The
lowest power operation is achieved using the global power-down pin. This active high
pin powers down every circuit in the device, including all clocks.
Individual ports can be powered down using the control register bit 0.11 of LXT973
(software power-down). This bit powers down a significant portion of the port, but
clocks to the register section remain active. This allows the management interface to
remain active during register power-down.
MFUNC5 pin on the PCI1520 device should be configured as GP output and can be
used to control the power-down pin of Ethernet PHY. The same pin is used to place
XR16L2551 DUART in PowerSave mode. Placing the LXT973 into near-zero power
state can reduce the power consumption of the VULCAN by 500mW. Please refer to
the LXT973 datasheet, on the Development Kit CD, for information about power
management.
MFUNC5
UART Operation Status
PHY Operation Status
0
Normal operation
Normal operation
1 PowerSave
Global
power-down