sleep mode entry philosophy

[llebotlan]

Posted on April 09, 2007 at 11:53

sleep mode entry philosophy

[llebotlan]

Posted on April 05, 2007 at 12:33

Hi,

I work on a STR710, on a custom board.

I have mistakes in my sleep mode entry fonction. I think I do not manage it with the correct philisophy.

First of all, I though I should switch off component in that order:

external device, IO, embeded devices and finaly the core.

But now, I am wondering if this logic is correct? For my problem, I suspect that way can produce wrong interruptions and wakeup cases.

But the core should be switch off at the end of course. So I suspect there is a specific theorie on it.

I try to develop a modular software environnement. That's why I try to divide the sleep mode entry into several modules : application, external device...

Is there a well known theory about it.

Thank you for your help,

[kaouther]

Posted on April 06, 2007 at 07:20

Hello,

The switch off components or peripherals or the core depends on which Low power mode do you need to configure your system. Is it WFI , LPWFI, Stop mode or Standby mode? For example in Stop mode, the core and peripherals clocks are stopped, you can also stop the Main Voltage Regulator and the FLASH in power-down mode, stopping the external oscillator ...

What is the low power mode required for your application?

There is not really a philosophy for that but there are some requirements to enter and exit from each lower mode.

Regards. ;)

[llebotlan]

Posted on April 06, 2007 at 09:39

Hi,

The low power mode is LPWFI. We already stopped, flash, oscillator...

I agree, there is some requirements. What I am wondering, is existing some standard requirements ? not functional one, but necessary for microcontrolers and operating systèms.

What I want is drivers managing the low power mode. But, from application point of view, it should be transparent.

[kaouther]

Posted on April 09, 2007 at 11:53

Hi,

It could be some standard requirements for microcontrollers but the most important to focus on the product requirements, here the STR710.

If the external oscillator is stopped, after wake up the system clock will remain CK_AF. You need to make sure that the external oscillator is enabled; if you want to execute your program at ful speed after wakeup otherwise it will remain CK_AF. Please refer to Figure 12 an example of LPWFI mode using CK_AF for detailed description.

Regards.