PIC18F47J53 CCS C Compiler 5.090 Sleep vs Deep Sleep

[Marco27293]

Hi,

I have a very well working firmware using deep sleep in order to minimize consumes.

In past projects I used external interrupt 0 hardware connected to PIN_B0 to successfully exit DS.

Unfortunately, my new hw needs to be waked-up by an external interrupt mapped on PIN_C1 pin (e.g. INT_EXT1), so I cannot exit DS anymore.

I would like to use Slepp mode, but I have a couple of questions:

1) Is it possible to exit Sleep using INT_EXT1 or INT_RTC (triggered by a previously set rtc_alarm)? if yes which register bits I need to clear/set ? (I know in asm I can do:
BCF IDLEN
BSF GIE
BCF INT1IF
BSF INT1IE
BSF DSEN
SLEEP
but what about INT_RTC ?

2) What are the mainly differences between Sleep and DS modes regarding power consumption ? In DS I reduce consumes up to 15uA, which is the best
could I got with Sleep mode?

Regards,

Marco

[temtronic]

Though I don't use that PIC, I dled and read the datasheet.
Section 4.5.0 says that ANY interupt will 'wakeup' the PIC from 'sleep' mode.

I didn't read about the power vs sleep modes though. Generally speaking ,reducing power involves turning off all unecessary peripherals,setting I/O pins and using high value pullups.
To me anything less than 10ma IS 'low power'....

Jay

[Marco27293]

I need a more detailed reply.

Which bits I need to set/clear before sleep in order to enable INT_RTC on RTC alarm during sleep?

For my application there is an enormous difference between few uA and few mA power consume (actually we're speaking of a x1000 factor!!)

Please give me a detailed feedback,

Marco

[temtronic]

You should read the CCS manual, have a look at some of the examples they supply as I don't use your PIC though the overall process is the same I mainly use the PIC18F46K22 series with an external RTC.
Using the internal RTC would simply need to enable that interrupt and cut a ISR. Similar process as coding for any interrupt.

[jeremiah]

15uA seems really high to me for deep sleep. Most of my PIC24 chips draw 100's of nA in deep sleep. At the end of your datasheet is a section called "Electrical Characteristics". It will tell you the expected current values based on your configuration.

As far as how interrupts are setup for sleep. There really isn't anything special that needs to be done to have them work in sleep mode. They just do. So if you turn on the EXT1 functionality (on PIC24's it is usually via #pin_select, but I don't know your chip), then the interrupt will automatically wake it from sleep and set the IF bit for that interrupt.

[Ttelmah]

Understand that a 'wake' from deep sleep involves a reboot of the chip.
It does a POR when you wake from this mode. You have to reprogram
all of your RAM variables etc.. All data is lost when you use deep sleep.
From the data sheet:

[Marco27293]

Hi,

I'm actually have problems to enter in sleep mode:

setup_wdt(WDT_OFF); // disabilito WDT
while(RTCSYNC);
#asm
BSF REGSLP
BCF IDLEN
BCF GIE
BCF DSEN
SLEEP
#endasm

It seems after few seconds that the code resumes to be processed from the subsequent instructions after the above code... Why?
How can I fix?

The weird thing is that deep sleep works perfectly:

setup_wdt(WDT_OFF);

while(RTCSYNC);
#asm
BSF DSWDTEN
BSF REGSLP
BCF IDLEN
BCF GIE
BSF DSEN
SLEEP
#endasm

[Ttelmah]

Use the compilers sleep instructions.
However the wake up, suggests that you have something left running
that is waking the chip. A timer, interrupt etc.

[Marco27293]

Interrupt are disabled (BCF GIE).
Timers are disabled.
Only RTCC works.

If I use sleep(); like suggested by the compiler nothing changes...

Please, help me, I do not know what could be the problem...

I repeat, Deep sleep is working, BUT I need sleep mode.

[PCM programmer]

[Ttelmah]

Disabling GIE, will still allow interrupts to wake the chip. In fact it'll not go to
sleep if any of the 'wake source' interrupt flags is set. I suspect this is your
problem.
You have to clear all the interrupts before you try to sleep. Remember
though that some interrupts cannot be cleared without the event being cleared.

[Marco27293]

Hi Ttelmah,

I cleared all interrupts previously enabled with clear_interrupt(level);

I also disable timer1 and turn off timer0.

It does NOT fix the sleep issue, code exits sleep after few seconds...

[Ttelmah]

As I already pointed out, some interrupts have to be serviced, or they
cannot be cleared. INT_RDA is an example of this. You cannot clear
INT_RDA, you have to read the character.
However 'after a few seconds', says that something is waking the chip
Obvious one is watchdog. You do understand that if the watchdog is
enabled in hardware, it cannot be turned off in software. You can only
disable in software, if the watchdog is enabled in software not by the
hardware fuses.
Something is waking your chip. You need to work out 'what'.

[Marco27293]

Hi,

these are my fuses:

#FUSES RTCOSC_INT
#FUSES WDT,WDT1024
#FUSES DSWDT,DSWDTOSC_INT
#FUSES DSWDT_=12
#FUSES NOPROTECT
#FUSES NOIOL1WAY

I think watch dog could be the problem. I need while main code runs, but I need to turn-off it during sleep, I've already tried via software with:

setup_wdt(WDT_OFF);

How can I fix this weird situation ?

[Ttelmah]

Disable the watchdog in your fuse.

Then enable the watchdog at the start of the code with setup_wdt.

If you look at the watchdog fuse in the data sheet: