topic Re: Sleep Mode in LPC1343 in LPCXpresso IDE

Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:21 GMT

Content originally posted in LPCWare by straw_hat on Fri Aug 19 00:34:57 MST 2011
Hello everyone. I would just like to ask where do the MCU go after a wake up interruption was made during sleep mode. I am using the LPC1343, the flow goes like this, I program a task and if you push the switch in short period three times, it goes to sleep and i set a pin for its wake up. Then after the wake-up my expectation is that is f push the switch again three times in a short period, it would go back to sleep but in my situation it doesn't. So after the wake up, where does the status of my MCU goes. Thanks

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:22 GMT

Content originally posted in LPCWare by Rob65 on Fri Aug 19 01:28:14 MST 2011
What do you do?
And are you talking about sleep mode or deep sleep mode?

In sleep mode only the clock to the processor is stopped, everything else keeps running.
Sleep mode is entered after the WFI instruction is found in your code. Your code stops at this point and the processor clock is halted. As soon as an interrupt is triggered (e.g. any interrupt from any active peripheral) the processor 'wakes up' again, executes the corresponding interrupt handler and then continues with the code that is placed after the WFI instruction.

I am not sure how you are thinking that pushing a switch three times will enter sleep mode again? That will only happen if you program your code to do this. Sleep mode is only entered when the WFI instruction is found in your code.

I suggest to carefully read the user manual (the sleep modes are not that easy) and study the examples delivered with the LPCXpresso software.

Regards,
[INDENT]Rob
[/INDENT]

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:23 GMT

Content originally posted in LPCWare by straw_hat on Fri Aug 19 01:42:07 MST 2011
Thanks Rob.

Yeah I bet low power mode is hard. By the way I am using the deep sleep mode. What I'm doing right now is that if the user will press the switch three times in short time interval, it will go to deep sleep mode. When it is press 1 short and 1 long, it will go execute other task. So basically what I am concern right now is that at the beginning of the code execution. There will be an LED that will blink and after I press the switch 3 times to enter deep sleep, the LED will be of, so after i wake up the MCU, I am expecting that the LED will blink again but in my case it is still off. So I am really confuse if after the wake up, where does the status of my MCU goes. Thank you. Sorry for my english

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:23 GMT

Content originally posted in LPCWare by Rob65 on Fri Aug 19 03:20:56 MST 2011

Quote: straw_hat
By the way I am using the deep sleep mode.

I have not looked at this in detail.
One of the differences between sleep mode and deep sleep mode is that most of the clocks are switched off as soon as deep sleep mode is entered.
This means that you have to re-enable these clocks as soon as your device wakes up again. Most likely that is why your LED does not blink anymore: the clock to the timer is stopped.

Otherwise try sleep mode first, anything that works in deep sleep also works in sleep mode. Deep sleep just needs some extra initialization for the whole system to be operational again.

There is an example called "timedwakeup" for the lpc11xx (look at the examples in LPC11xx/NXP_LPCXpresso1114-302....zip
As far as I remember the lpc11xx deep sleep mode is similar to the lpc13xx one. Unfortunately I am currently working with the lpc175x so that information is now hidden in the far section of my brain :eek:

Quote:

So I am really confuse if after the wake up, where does the status of my MCU goes.

Your program starts executing the interrupt and the program continues right after the WFI but as stated above you will need to enable the peripheral clocks yourself.

Rob

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:24 GMT

Content originally posted in LPCWare by NXP_USA on Fri Aug 19 15:00:10 MST 2011
Hi,

There is also LPC13xx app note/software example you can look at:
http://ics.nxp.com/support/documents/microcontrollers/zip/an10973.zip

It talks about the wake-up implementation for each mode and wake-up times.
Software example should show what initialization steps are needed.

Thanks.

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:25 GMT

Content originally posted in LPCWare by straw_hat on Sun Aug 21 20:26:45 MST 2011
hello,

Thanks for the reply. About the application notes from NXP, I already got one. Regarding the self wake up, the part of the code that I dont understand is the config_ios(); Can you please tell me what is the main purpose of that function. My understanding is that it configures the IOS after the wake up, so after the wake up will that code reconfigures my previous configuration of the GPIO. Please help me out because my knowledge is too narrow. Thanks

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:25 GMT

Content originally posted in LPCWare by ktownsend on Mon Aug 22 03:37:14 MST 2011
Unless you have changed the GPIO pin state yourself, both sleep and deep sleep will retain the previous pin config settings. What you DO need to reconfigure after waking up from deep sleep is the system clocks (as mentionned earlier), such as reconfiguring the PLL, switching back to the external crystal as the clock source instead of the WDT oscilllator, etc.

To get the lowest possible power consumption in deep sleep, however, you may very well need to change the state of the GPIO pins manually before sending the WFI signal and entering deep sleep. I believe the app note example from NXP sets all the pins to input and GND (off the top of my head, which should give you the lowest power consumption in many situations). That means that before you go into deep sleep you will need to record the GPIO pin states somwhere in memory, and when you come out of wakeup you will need to set them back to an appropriate state. I imagine the app not from NXP deals with this, though.

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:26 GMT

Content originally posted in LPCWare by straw_hat on Mon Aug 22 17:14:55 MST 2011
hello

Thanks for the clarification. So if I did reconfigure manually the clocks etc back to its normal condition, will the MCU resume its previous state before it enters the deep sleep mode??:confused: For example, I blink the LED before it enters the deep power down mode, when I wake it up, the LED will resume blinking??Thank You

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:26 GMT

Content originally posted in LPCWare by ktownsend on Tue Aug 23 00:24:38 MST 2011

Quote: straw_hat
hello

Thanks for the clarification. So if I did reconfigure manually the clocks etc back to its normal condition, will the MCU resume its previous state before it enters the deep sleep mode??:confused: For example, I blink the LED before it enters the deep power down mode, when I wake it up, the LED will resume blinking??Thank You

The best way to know is to try it :-)

But yes ... after waking up, it will continue executing the code where it left off (after firing the wakeup interrupt).

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:27 GMT

Content originally posted in LPCWare by straw_hat on Tue Aug 23 01:23:22 MST 2011
hello. I already tried but the code is not executed unless it is under the WAKEUP_IRQHandler funcrtion. So is there any other way for me the call the program after it exit at the deep sleep mode???Thanks

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:27 GMT

Content originally posted in LPCWare by serge on Tue Aug 23 03:31:33 MST 2011
Just re-activate the clocks in the IRQ handler. After the MCU leaves the IRQ handler he should just continue your program without the need to call anything.
Rob will correct me if i am wrong (i hope :rolleyes: )

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:28 GMT

Content originally posted in LPCWare by ktownsend on Tue Aug 23 09:28:41 MST 2011

Quote: straw_hat
hello. I already tried but the code is not executed unless it is under the WAKEUP_IRQHandler funcrtion. So is there any other way for me the call the program after it exit at the deep sleep mode???Thanks

You have a problem somewhere in your code, then.

What are you putting in the WAKEUP_IRQHandler? You'll really need to post some meaningful code before anyone can help you.

Are you clearing the DEEPSLEEP bit in the system control register, for example (SCB SCR). Are you disabling the timer that you (possibly) used to wake the device up from deep sleep?

It SHOULD continue executing wherever it left off before going into deep sleep (after the ISR mentionned above executes).

Have you tried turning an LED on inside the IRQHandler mentionned above to see if you are waking up?

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:29 GMT

Content originally posted in LPCWare by straw_hat on Tue Aug 23 17:09:17 MST 2011

Quote: KTownsend

What are you putting in the WAKEUP_IRQHandler? You'll really need to post some meaningful code before anyone can help you.

Im put my code in WAKEUP_IRQHandler to blink my LED

Quote: KTownsend

Are you clearing the DEEPSLEEP bit in the system control register, for example (SCB SCR). Are you disabling the timer that you (possibly) used to wake the device up from deep sleep?

Yes sir I clear DEEPSLEEP bit, and disable the timer, anyway I'm not using the self wake-up, I used the external PIN to wake up from deepsleep mode.

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:29 GMT

Content originally posted in LPCWare by straw_hat on Tue Aug 23 17:15:31 MST 2011

Quote: Serge
Just re-activate the clocks in the IRQ handler. After the MCU leaves the IRQ handler he should just continue your program without the need to call anything.
Rob will correct me if i am wrong (i hope :rolleyes: )

ahm...I already did that sir but still the last program doesn't continue after the wakeup:(:(:(

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:30 GMT

Content originally posted in LPCWare by serge on Tue Aug 23 23:21:56 MST 2011
A pure rethorical question: what happens when a device goes into sleep or deep-sleep mode when servicing a IRQ request?:cool:

And just like Ktownsend said: you should post your code before we can help you out. :D

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:31 GMT

Content originally posted in LPCWare by Rob65 on Tue Aug 23 23:45:53 MST 2011

Quote: straw_hat
but still the last program doesn't continue after the wakeup:(:(:(

There are a number of things that you most likely still missed.
Check the description of PDSLEEPCFG, PDWAKECFG and PDRUNCFG in the user manual. Also check which oscillator you are using. If you are running from the system oscillator with the PLL switched on you will not be able to properly wake up and continue where you left (the PLL is switched of during deep sleep).

I urge you to read the application note that NXP_USA posted and start with the example from that (zip) file. The projects are in LPCXpresso format so that is as easy as importing the project, compile and run.
[B]But do read the PDF document, it contains vital information.[/B]

The application note is really the only viable way to start exploring the different sleep and power down modes. Your application contains too many other things that can go wrong.
Start with the LPC1300_wakeup.zip and add your blinking LED in that application before doing anything else.

Regards,[INDENT]Rob
[/INDENT]

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:31 GMT

Content originally posted in LPCWare by straw_hat on Wed Aug 24 00:01:38 MST 2011
hello rob.

yes sir i already did everything. I already did read the user manual and the application notes for low power modes from nxp, in fact I try the code that the nxp provided. but still my programs go nasty after the wake up, I tried to put a program that blinks an LED to the WAKEUP_IRQHandler function and it works, so is it true that after the wake up, the MCU will only execute the code inside the WAKEUP_IRQHandle():confused::confused:..thank you very much

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:32 GMT

Content originally posted in LPCWare by serge on Wed Aug 24 00:16:05 MST 2011
Could it be a stack related problem? I noted that the __WFI instruction is in a subroutine.

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:33 GMT

Content originally posted in LPCWare by straw_hat on Wed Aug 24 01:01:57 MST 2011
hi.

i dont have any idea if where the problem is now. because i only integrated the deep sleep mode in my program, and it is already wide.:confused::eek:..thats why i just copied the code from nxp and modify the pins..hehehe

Re: Sleep Mode in LPC1343

lpcware — Wed, 15 Jun 2016 22:20:33 GMT

Content originally posted in LPCWare by ktownsend on Wed Aug 24 04:24:41 MST 2011
I don't know how useful this is to you since I'm using my own library and header (not CMSIS, etc.), but perhaps you'll spot something you're missing:

https://github.com/microbuilder/LPC1114CodeBase/tree/master/core/pmu

You can call the deep sleep function to either use a timed wakeup or not. This code works perfectly for me. It's for the 1114, but the 1343 is identical in every meaningful respect for deep-sleep and waking up.