Eurotech Appliances VIPER / VIPER-LITE PXA255 - Manual (Page 84)

VIPER Technical Manual Power and power management
© 2007 Eurotech Ltd Issue E 84
Audio power management
The audio interface supports the AC’97 low power modes. Shutting down the digital
and analogue interfaces can reduce consumption by up to 38mA ±3mA (190mW
±15mW).
To shut down the AC’97 Codec, the software must write to the relevant bits in the
Powerdown Control / Status Register (26h). Please see the LM4549 datasheet
contained on the Development Kit CD.
TPM
If the VIPER has the TPM option the VIPER consumes a further 3.5mA (17.5mW)
while the TPM IC is idle, and 17mA (85mW) while the TPM IC is operating. This device
cannot be shutdown.
Wake up events
When the PXA255 processor is placed into sleep mode, two sources can be used to
wake the processor.
Source GPIO
USER_CONFIG1 GPIO7
RTC Alarm Internal
See section 3.5 in the PXA255 Applications Processor Developers Manual, included in
the Development Kit CD.
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