Working stop working why ? 33EV32GM002

[1980best]

Hi everybody,
Is there a problem with my devices ?
Device first working after stop +++ after working after stop .. again

Where is the problem ?
osc ?
My crystal is 8 MHz, I want it to be working 80 MHz - 140 MHz.

[temtronic]

While I don't use that PIC, I'll offer some comments.

You're using an 8 MHz xtal.
Have you the proper caps for it?
Depending on xtal, you may need a small series R.

There has been a fair amount of posts simlar to yours, so 'search' here and see what has been said.

I'd actually try the internal 4MHz oscillator. That has to work....Since no external parts are needed, it's just a matter of selecting the correct 'fuses' and delay(options...) to make it run.
Also it removes any PCB problems like solder whiskers.

Jay

[1980best]

Thanks for answer me,
but
I want to working 80MHz & 140MHz.

It is very speed devices.

Maybe my problem:
setup_oscillator(?);

[jeremiah]

I know a lot of the dspic33 devices cannot startup with the PLL so you generally startup with the internal and then switch to the oscillator + PLL.

Try messing around with something like this:

[1980best]

However, my problem no startup.

My devices normally working, maybe 2-5 minutes.

after reset ...

I see my led toogle and devices working.

But after reset wait delay_ms(5000); delay_ms(5000); (led off !!)

after, continuous led toggle.

[temtronic]

I reason I suggested to run at 4MHz internal is to PROVE the PIC functions. It should run for hours if not days not just 2-5 minutes.

You could have a thermal problem...or a power supply problem.

Does the PIC get hot when it fails?
What is the power supply? Being 33 series, I assume 3 volts?? what's the ripple content?? What's the current draw ??

What 8MHz xtal ?? Again, if you run the PIC from the internal osc and it works fine, then that shows you the external xtal parts(xtal,caps) have a problem...wrong values, poor PCB, etc.

There is NO point in trying to get 80-140 MHz speed if the PIC fails at 4MHz. Also the faster you go, the more critcal it is to have proper power supply, bypass caps, heat sinking, etc.

Jay

[Ttelmah]

First thing to understand is you can go to 140MHz with the internal oscillator (or very close to it). The PLL on these chips is not the simple *N PLL that more basic PIC's have. It has a programmable multiplication factor from 2* to 514*. This section has an input clock requirement of 0.8 to 8MHz, and is preceded by a programmable divider giving /2 to /34. It is then followed by another programmable divider giving /2 /4 /6 & /8.
Now unlike the basic PLL, this is all controlled in software, not by the fuses. The chip wakes in a default mode, and then the clock is reprogrammed once it has started. Also if the incoming clock would give an invalid operation with the default settings, then the chip wakes using the INTRC and only switches to the external oscillator after the factors are all setup.
The internal oscillator is 7.37MHz. It can give you with a division of 8, a multiplier of 304*, and a division by 2, 139.6Mhz. This is the default 'fast' setting for the chip.
The only reason to lose pins for an external oscillator is if you need the extra clock accuracy.

Do something really basic like:

[1980best]

5V>Led>1K>Pic pin
5mA sink current or source
Power 5V

[temtronic]

hmm 5 volt.. I thought all 32 PIC were 3 volts then I reread and see the device header....33ev.... NOT a dsPIC32 series device ?
Perhaps an evaluation board ??

You should post exactly what hardware you are using.
I had assumed it was a PIC on your PCB, hence my comment about possible power supply problems. If this is an 'evaluation module', perhaps it came with preloaded software(debugger / monitor) or some other 'custom' interface to the PC. Maybe there's a dip switch or jumper that needs to be changed ??
If it is a Microchip product they will have a lot of apnotes for it.

Without more information I can't help any more,aside from general possible causes...

Jay

[RF_Developer]

[Ttelmah]

[temtronic]

As Mr. T says....
They are fussy about the capacitors on the Vcore, and ripple here can cause erratic behaviour.

I downloaded the dtaasheet for the 'family'.
Not exactly a 'beginners PIC'.
It'd be interesting to find out WHAT board layout the OP has. My gut tells me it ain't '25 year old white breadboard' compatible.

Being a new PIC, perhaps the header or compiler has a bug in it BUT erratic operation, like the 2-5 minutes..., just smells like a power problem.

It'll be nice to see [solved] and HOW for this thread.

Jay

[1980best]

PRIMARY OSCILLATOR (POSC)
The Primary Oscillator (POSC) is available on the OSC1 and OSC2 pins of the dsPIC33E/PIC24E
device family. This connection enables an external crystal (or ceramic resonator) to provide the
clock to the device. Optionally, and depending on the device, it can be used with the internal PLL
to boost the system frequency (FOSC) up to 140 MHz for 70 MIPS execution. The primary
oscillator provides three modes of operation.


• Medium Speed Oscillator (XT Mode)
The XT mode is a medium gain, medium frequency mode used to work with crystal
frequencies of 3.5 MHz to 10 MHz.


• High-Speed Oscillator (HS Mode)
The HS mode is a high-gain, high-frequency mode used to work with crystal frequencies of
10 MHz to 25 MHz.

http://ww1.microchip.com/downloads/en/DeviceDoc/70580C.pdf

[1980best]

Section 8. Reset

INTRODUCTION
The Reset module combines all the reset sources, and controls the device Master Reset Signal,
SYSRST. The following is a list of device Reset sources:
• POR: Power-on Reset
• BOR: Brown-out Reset
• MCLR: Master Clear Pin Reset
• SWR: RESET Instruction
• WDTO: Watchdog Time-out Reset
• CM: Configuration Mismatch Reset
(This source is not available on all devices. Refer to the specific device data sheet for
details.)
• TRAPR: Trap Conflict Reset
• IOPUWR: Illegal Condition Device Reset
- Illegal Opcode Reset
- Uninitialized W Register Reset
- Security Reset

http://ww1.microchip.com/downloads/en/DeviceDoc/S8.pdf

[Ttelmah]

So, you are reading the data sheet at last.