Guo Yang-

> TI C6000 has three powerdown mode ,among them,
> there are two mode which could only be waken up by
> reset, according to the document. So I don't know
> whether the DSP could distinguish between reset in
> powerdown mode or not.

After Reset, the DSP would not know unless you stored something in a special internal
SRAM location that is "outside" the normal C code environment. For example, you
could store a unique signature of several bytes just prior to entering PD2 or PD3.
Then after Reset, your code can look at this location to determine if it's a power-on
Reset or power-down recovery Reset. It will take some coding work on your part to
"go back" to original execution state prior to power-down.

I assume you have this document:

http://focus.ti.com/lit/ug/spru728c/spru728c.pdf

The issue with Reset is that so many things will get Reset -- SDRAM control
registers, interrupts, etc. For instance, putting the unique power-down indicator
signature in SDRAM would be a bad idea. And if you let code run from c_int0 entry
point, then entire C code environment (not to mention DSP/BIOS) will be
re-initialized. So you have to be very careful about how you handle this.

Good luck!

-Jeff

> --- Jeff Brower д
>
> > Guo Yang-
> >
> > > I am a little confused about power down through
> > > reset.
> > > TI C6000 DSPs have power down mode which could
> > > reduce power consumption. Power down mode could
> > stop
> > > clock of the chip, which could be waken up by
> > reset.
> > > After wakeup, the program could continue its
> > > execution. Did anybody succeeding in using this
> > > function?
> > > I use TI C6711 DSK and XDS510 emulator, after I
> > go
> > > into power down mode through writing CSR register,
> > I
> > > press the reset button on DSK, but it seemed that
> > the
> > > program run away. It could not continue its normal
> > > execution.
> > > Could anyone help me?
> >
> > I believe the C6x DSPs can wake up from power-down
> > mode using an external interrupt.
> > In that case, program execution would resume from
> > where it left off.
> >
> > If you apply Reset signal, then the chip will
> > *always* reset and run from Reset
> > Vector -- *everthing* on the chip is reset. This is
> > why they call it "reset" :-)
> >
> > -Jeff Start a New Thread

Hi, Jeff

Thanks for your reply.

TI C6000 has three powerdown mode ,among them,
there are two mode which could only be waken up by
reset, according to the document. So I don't know
whether the DSP could distinguish between reset in
powerdown mode or not.

Guo Yang
--- Jeff Brower д

> Guo Yang-
>
> > I am a little confused about power down through
> > reset.
> > TI C6000 DSPs have power down mode which could
> > reduce power consumption. Power down mode could
> stop
> > clock of the chip, which could be waken up by
> reset.
> > After wakeup, the program could continue its
> > execution. Did anybody succeeding in using this
> > function?
> > I use TI C6711 DSK and XDS510 emulator, after I
> go
> > into power down mode through writing CSR register,
> I
> > press the reset button on DSK, but it seemed that
> the
> > program run away. It could not continue its normal
> > execution.
> > Could anyone help me?
>
> I believe the C6x DSPs can wake up from power-down
> mode using an external interrupt.
> In that case, program execution would resume from
> where it left off.
>
> If you apply Reset signal, then the chip will
> *always* reset and run from Reset
> Vector -- *everthing* on the chip is reset. This is
> why they call it "reset" :-)
>
> -Jeff Start a New Thread

Guo Yang-

> I am a little confused about power down through
> reset.
> TI C6000 DSPs have power down mode which could
> reduce power consumption. Power down mode could stop
> clock of the chip, which could be waken up by reset.
> After wakeup, the program could continue its
> execution. Did anybody succeeding in using this
> function?
> I use TI C6711 DSK and XDS510 emulator, after I go
> into power down mode through writing CSR register, I
> press the reset button on DSK, but it seemed that the
> program run away. It could not continue its normal
> execution.
> Could anyone help me?

I believe the C6x DSPs can wake up from power-down mode using an external interrupt.
In that case, program execution would resume from where it left off.

If you apply Reset signal, then the chip will *always* reset and run from Reset
Vector -- *everthing* on the chip is reset. This is why they call it "reset" :-)

-Jeff Start a New Thread

Hi, Everyone

I am a little confused about power down through
reset.
TI C6000 DSPs have power down mode which could
reduce power consumption. Power down mode could stop
clock of the chip, which could be waken up by reset.
After wakeup, the program could continue its
execution. Did anybody succeeding in using this
function?
I use TI C6711 DSK and XDS510 emulator, after I go
into power down mode through writing CSR register, I
press the reset button on DSK, but it seemed that the
program run away. It could not continue its normal
execution.
Could anyone help me?
GuoYang Start a New Thread