Cortex M3 realworld wakeup times and power consumption

Hi,

I am looking at using a Cortex M3 based mcu for an application
requiring a very fast wakeup time and low power during that sleep
mode.

Is it possible for the M3 to wake up in less than 300us given that
whatever sleep mode it is in has to draw less than 300uA?

thanks,

Mike.

MealMan401 wrote:

> Is it possible for the M3 to wake up in less than 300us given that
> whatever sleep mode it is in has to draw less than 300uA?

Yes, it is. SMT32 series has 2 power down modes.
In STANDBY mode in consumes 2uA (typ.) and wakes up in less than 2uS.
In STOP mode in consumes 14uA (typ.) and wakes up in less than 40uS.

Regards,
~ Ale�

Ale� Svetek wrote:
> Yes, it is. SMT32 series has 2 power down modes.

Actually it is STM32, not SMT32. You can find more
info about low-power modes of this series on ST web site.
Look for application note AN2629.

~ Ale�

On Dec 16, 12:49=A0am, Ale=9A Svetek <svetek.a...@gmail.com> wrote:
> MealMan401 wrote:
> > Is it possible for the M3 to wake up in less than 300us given that
> > whatever sleep mode it is in has to draw less than 300uA?
>
> Yes, it is. SMT32 series has 2 power down modes.
> In STANDBY mode in consumes 2uA (typ.) and wakes up in less than 2uS.
> In STOP mode in consumes 14uA (typ.) and wakes up in less than 40uS.
>
> Regards,
> ~ Ale=9A

I believe STM is releasing a low power version (STM32L) next year with
STOP/STANDBY at 2/1uA , respectively.

On 2008-12-16, Ale? Svetek <svetek.ales@gmail.com> wrote:
> MealMan401 wrote:
>
>> Is it possible for the M3 to wake up in less than 300us given that
>> whatever sleep mode it is in has to draw less than 300uA?
>
> Yes, it is. SMT32 series has 2 power down modes.
> In STANDBY mode in consumes 2uA (typ.) and wakes up in less than 2uS.
> In STOP mode in consumes 14uA (typ.) and wakes up in less than 40uS.

That seems very odd.  On all other processors I've used, the
lower the power consumption for a mode, the longer the wakeup
time.  In this case it seems to be the opposite.

You'd have to be nuts to use STOP mode, since it's both 7X
higher power and takes 10X longer to wake up.

-- 
Grant Edwards                   grante             Yow! ... this must be what
                                  at               it's like to be a COLLEGE
                               visi.com            GRADUATE!!

On Dec 16, 7:37 am, Grant Edwards <gra...@visi.com> wrote:
> On 2008-12-16, Ale? Svetek <svetek.a...@gmail.com> wrote:
>
> > MealMan401 wrote:
>
> >> Is it possible for the M3 to wake up in less than 300us given that
> >> whatever sleep mode it is in has to draw less than 300uA?
>
> > Yes, it is. SMT32 series has 2 power down modes.

It's easy to remember: STM32 is ST's M32 uC.

> > In STANDBY mode in consumes 2uA (typ.) and wakes up in less than 2uS.
> > In STOP mode in consumes 14uA (typ.) and wakes up in less than 40uS.
>
> That seems very odd.  On all other processors I've used, the
> lower the power consumption for a mode, the longer the wakeup
> time.  In this case it seems to be the opposite.
>
> You'd have to be nuts to use STOP mode, since it's both 7X
> higher power and takes 10X longer to wake up.

With regulator off in standby mode, you might not be able to preserve
I/O states.
Just my guess for now, I have to study it further.

>
> --
> Grant Edwards                   grante             Yow! ... this must be what
>                                   at               it's like to be a COLLEGE
>                                visi.com            GRADUATE!!

On Dec 16, 10:37=A0am, Grant Edwards <gra...@visi.com> wrote:
> On 2008-12-16, Ale? Svetek <svetek.a...@gmail.com> wrote:
>
> > MealMan401 wrote:
>
> >> Is it possible for the M3 to wake up in less than 300us given that
> >> whatever sleep mode it is in has to draw less than 300uA?
>
> > Yes, it is. SMT32 series has 2 power down modes.
> > In STANDBY mode in consumes 2uA (typ.) and wakes up in less than 2uS.
> > In STOP mode in consumes 14uA (typ.) and wakes up in less than 40uS.
>
> That seems very odd. =A0On all other processors I've used, the
> lower the power consumption for a mode, the longer the wakeup
> time. =A0In this case it seems to be the opposite.
>
> You'd have to be nuts to use STOP mode, since it's both 7X
> higher power and takes 10X longer to wake up.
>
> --
> Grant Edwards =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 grante =A0 =A0 =A0 =A0 =
=A0 =A0 Yow! ... this must be what
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 at =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 it's like to be a COLLEGE
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0visi.com =
=A0 =A0 =A0 =A0 =A0 =A0GRADUATE!!

you are right, he has the times reversed, stop keeps RAM active