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Subject: Re: HDD off, backlight off, idle 94 mA

Re: HDD off, backlight off, idle 94 mA

From: Daniel Stenberg <>
Date: Tue, 14 Jan 2003 18:12:05 +0100 (MET)

On Tue, 14 Jan 2003, Joaquim Carvalho wrote:

> I read a brief SH1 datasheet and it has a standby mode that should be used
> to reduce power consumption.

It has both SLEEP and STANDBY.

> I have never programmed this chip but from my past working experience with
> other processors there should be a HLT, HALT or SLEEP instruction that
> stops or ignores the clock until some external event occurs. A power
> consumption of a couple of mA should be achievable (even a 386 can do that)
> Has anyone investigated this?

Of course. First, SLEEP is the one we can use as we can't awake from STANDBY
without an external IRQ.

SLEEP is 20mA less hungry.

To make use of this properly, we need to rewrite our thread scheduler so that
we have the list of threads sorted and in a queue for running.

The Player model needs to poll the MAS every millisecond while playing if I'm
not mistaking.

Feel free to suggest and implement something that takes advantage of this.

> Also, 34mA is way too much for an LCD of that kind, looking at it I guess
> it uses less than 1mA

Well, we're all ears and eager to know what your guess is.

> > You mean the MAS? Read the spec sheet.

> I will as soon as the postman arrives with my recorder!

You won't get the MAS spec with your Archos you know... ;-)

 Daniel Stenberg -- --
Received on 2003-01-14

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