Sleep not sleeping

[ben_r]

Hi,

I'm trying to get my 18F2320 to sleep - but Im having difficulty. I have a suspicion it may be because Im using the Internal clock - but cant find any documentation to back this up.

The code in its reduced form is :

[PCM programmer]

In the 18F2320 data sheet, in section 3.1.2,
it has this highlighted remark:

[Guest]

My 18F4320 would not sleep and wake properly with Timer 2 running, though it works fine with only the ADC timer running. I never did solve the problem.

I don't know if this helps you, but the reason I never solved the problem is that I found that 10-bit ADC conversions are pretty steady even in the LSB, whether or not the processor is sleeping during the conversion. I am using a linear reg supply for VDD with a 0.33 uF ceramic bypass cap.

gordon

[cbstieff]

The following code is used to create 8 interupts per second from a 32KHz external crystal on Timer1. There are a lot of pieces of code required to do the job. For more information read the Data Sheet sections on Interupts and Timer1.

---Code below ---

// assuming that there is a 32KHz crystal with the proper capacitors on the Timer1 I/O pins

// for 10ths (approximately)
//#define TIMER1INIT 62300
// for 8ths (exactly)
#define TIMER1INIT 61440

#define GIE_ONLY 0xF280

#byte OSCCON = 0xFD3
...

#INT_TIMER1
void Timer_1_ISR()
{
set_timer1(TIMER1INIT); // just reinitialize the timer - the interupt will restart the program when the ISR is returns
}

...

Main()
{ // All initialization code here

...

// initialize and setup Timer1
set_timer1(TIMER1INIT);
setup_timer_1(T1_EXTERNAL|T1_DIV_BY_1|T1_CLK_OUT); // setup external clock
// note a delay of as much as 20ms may be requird to allow the Clock to stabilize
enable_interrupts(INT_TIMER1); // enable the timer interupt
enable_interrupts(GLOBAL); // enable interupt processing
//the Timer1 ISR will now start processing 8 interupts per second wiether the CPU is in sleep mode or not
// note a delay of as much as 20ms may be requird to allow the Clock to stabilize

...

While (1) // do forever
{ // start main processing loop

// main processing loop MUST execute the code at sleeploop in less than 1/8 second or unexpected things WILL happen.
...

sleeploop:
disable_interrupts(GIE_ONLY); // Note this causes the execution to continue with the next instruction
// (after the sleep instruction rather than doing a Reset)
OSCCON |= 0x80; // set to idle mode
sleep(); // may not execute some instruction correctly when the CPU wakes up so make the first instruction a NOP
#asm ASIS
nop
#endasm
enable_interrupts(GLOBAL);
} // end main processing loop

[valemike]

I currently have a PIC16LF627A app:
1. A 9V battery regulated down to 3.3V. The device sleeps until the WDT times out or RB0 gets a falling edge. I use the internal 37Khz oscillator (thanks to PCM Programmer for that macro I cut and pasted from the archives)

The CCS-supplied function "sleep()" works just fine for me. However, I do not have other interrupts enabled, such as timer interrupts. I thought that these timers weren't generally supposed to run anyways while the pic is in sleep.