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Subject: [ rockbox-Feature Requests-530466 ] Low power mode
From: noreply_at_sourceforge.net
Date: 2002-03-15


Feature Requests item #530466, was opened at 2002-03-15 12:52
You can respond by visiting:
http://sourceforge.net/tracker/?func=detail&atid=439121&aid=530466&group_id=44306

Category: None
Group: None
Status: Open
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: Low power mode

Initial Comment:
Seeing as things are progressing quite well, let's see
what we can really do ;)

The SH-1 datasheet specifies that the serial port may
be run in DMA mode, to enable the fetching of data
independantly to program execution. The datasheet
also specifies that DMA may be run in sleep mode, and
the other on-chip support modules also run in sleep
mode.

So. This _implies_ that the serial port that feeds
the MAS chip can be run in DMA whilst the CPU is in
sleep mode. The CPU would essentially not be running
anymore, so it would not be able to update the LCD,
but this seems a minor bother to me, considering a
saving of at least 20% battery life. If possible (and
it still may not be), it would make a good system menu
option (low power / normal operation). There may also
be an advantage of noise reduction on the recorder, as
driving the LCD seems to be the source of this
problem ....

The CPU would need to exit sleep whenever the buffer
was running low, to spin up the HD and fill up memory
again.

Now, if only the DMA controller were hooked up to the
HD, the CPU wouldn't need to exit sleep so often ....

----------------------------------------------------------------------

You can respond by visiting:
http://sourceforge.net/tracker/?func=detail&atid=439121&aid=530466&group_id=44306



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