CC1110 PM2

Hi Ron.

Please have a look at the Basic Software Examples that can be found here:
http://focus.ti.com/docs/prod/folders/print/cc1110f32.html#toolssoftware

Once installed, the code you are looking for can be found here:
cc1110_cc2510_Basic Software_Examples\source\examples\pm\powermode2.c

Best regards,

Kjetil

Thanks Kjetil,

     I just found the info in the current TI newsletter. Exactly what I needed to wrap my little head around!

Ron

 Here's the next issue. I followed the source code to the letter, other than changing the active counter portion of the code to a quick transmit burst. The device should go to sleep at this point and then repeat in an endless while loop. What it does, is hard reset, then start from the beginning of the program again. The transmitted information is correct, so at least the crystal oscillator is initializing properly. Any idea as to where it is falling off?

Thanks,

Ron

Update... I found my mistake in the assembly listing. Thanks again! This forum is very helpful...

Here is the next issue. Everything works as advertised....But, the chip resets upon wake up. It never makes it to the next section of code. Also, the current drain goes down to 160uA with all ports as outputs, set low and no loads on them. Any ideas to get me further?

Thanks,

Ron

Hi Ron,

This should not happen. What does the SLEEP register say upon start-up/reset? Bits 3-4 tell's you the source for your reset.

Also..any chance that the voltage can drop below the brown-out threshold upon waking up?
Have you enabled watchdog in your code?

Rgds,
Kjetil

 I will check the sleep register value on wakeing. The same thing happen whether on battery or running on the programmer power supply. WDT is set to off. In frustration, I changed some values in the sleep and clockcon registers and it worked as it should, but the HS crystal oscillator kept running with a 3mA drain throughout the cycle. Not helpful but maybe a little more insight. I will change the chip next to see if I had a bad one. 

Update...

I changed the chip and it worked as expected and advertised. The only thing is that it starts at the main function when woken up, instead of inside the while(1) loop. Is this what it should do?

Thanks again for the help,

Ron

The CC1110 still resets on exiting PM2. the RST bits tell me that it is an "External Reset". I have the reset pin tied to B+ through a 2.2K resistor, and the trace to the programming header is less than 1" long. What else could be resetting it?

Hi.

Chapter 6.11.1 in the datasheet states:

The RESET_N pin is sensitive to noise and can cause unintended reset of the chip. For a long reset
line add an external RC filter with values 1 nF and 2.7 k close to the RESET_N pin. When doing
this, note that the RESET_N low width (the shortest pulse that is guaranteed to be recognized as a
reset pin request) is longer than stated in Table 19.

If the RST bits tell you the source is an external reset, then the source should be external.

Kjetil

Thanks for the reply. Late last night I tracked the problem down. One of the narrower power traces to the chip was undermined in the etching process right near the chip, so it was slightly resistive (on the order of a few ohms). Putting the scope pin on the trace showed no drop, but putting it on the chip pad, showed a slight voltage drop  and noise to that pin on startup. I would have thought this would be reflective in the RST bits as a brownout or a POR, but it showed as an external reset. The rest of the power traces were unaffected, so all else worked flawlessly. If it didn't cost me days of time, I'd say it was a good puzzle to figure out.

Thanks,

Ron

When coming out of PM2, it appears some ofthe radio registers are corrupted. I just reload them before transmitting, so it is not a problem, but is this an expected result? I don't see anything in the manual with regards to loss of these registers in power mode 2.

Thanks,

Ron

Hi.

The radio registers should have retention like described in Table 32 in the datasheet. If you experience anything else it would be nice to know which registers are not retained/corrupted.

Rgds,
Kjetil