VIPER Technical Manual

Power and power management

 

 

Audio power management

VL

TPM

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.

If the VIPER has the TPM option the VIPER consumes a further 3.5mA (17.5mW) VL 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.

SourceGPIO

USER_CONFIG1 GPIO7

RTC Alarm

Internal

 

 

See section 3.5 in the PXA255 Applications Processor Developers Manual, included in the Development Kit CD.

© 2007 Eurotech Ltd Issue E

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