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JMac3108

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  1. Anyone know where you can buy the connectors that come with the Launchpad? Not the headers that you solder onto the Launchpad, but the mating connectors that you would put on a prototype board that you plug into the Launchpad. Thanks.
  2. Thanks everyone for all the great information. I now know much more about the MSP430 DCO clock that I ever would have otherwise! I solved my problem today. It turns out that my Tektronix TDS 224 scope has a problem. I took the Launchpad to work and used a high end 500MHz Tektronix scope and the clock was very stable. Except, if I used HF REJECT trigger coupling. This makes sense because with this coupling the scope has a low-pass filter that would prevent it from properly seeing the fast edges on my 10MHz clock and would cause the trigger point to vary. This gave me a clue concerning the T
  3. I'm measuring SMCLK directly on the LaunchPad board - I don't have any additional circuitry attached yet. I can't say how much the jitter is because the signal is moving so much I can't get a trigger on the scope. Usually with clock jitter you can trigger on the leading edge and see the trailing edge jittering. In this case if I set the scope on auto trigger I get an EYE diagram, if I set it on HF Reject I can see the clock but its moving all over. This definitely makes me think the modulation is on and is moving the frequency. But, I set the MOD bits to zero in the DCOCTL register whi
  4. Zeke, Yes, I have it and its great. Often its better than the TI documentation IMO.
  5. It was mentioned that if I read back zeros for the MOD bits then its not likely that the clock modulation is running and causing my jitter. I'm using CCS and don't have it all figured out yet. When debugging I open a register watch window and have all the peripheral registers showing in it. I also clicked on the "continuous refresh" button. But all the registers say "unable to read" and if I double click on them to show the individual bits, they all read zero. Any ideas on what I'm doing wrong? I would feel better if I could manipulate the MOD bits and see them change. BTW, thanks for
  6. Oh, and based on something I read in a TI app note I added a delay before changing the clock settings to make sure that VCC is stable first. It didn't help of course.
  7. I'll try to respond to everything ... I'm looking at SMCLK on P1.4, thats where I'm seeing the DCO clock jitter. Yes, the jitter occurs at lower frequencies. There is no external source, no XT2 crystal. Just using the internal DCO oscillator. I do not believe that the DCO is inherently unstable. I'm seeing a LOT of jitter and its hard to believe the internal DCO oscillator is that bad. I'll get in touch with TI tomorrow and ask them about it. Thanks everyone for the comments. Keep them coming!
  8. Nuetron, No, I didn't calibrate it. I wasn't interested in absolute accuracy of the DCO so I wasn't worried about calibrating it at this point. With the settings I used the DCO is close enough to 10MHz for my purposes. However it is jittering all over. Much more than could be blamed on not being calibrated. It really appears as if the clock modulator is running even though I set all the MODx bits low. Have you seen this before and was it caused by lack of calibration? Thanks.
  9. Hi guys. I'm new to the forum and have a question that I hope someone can help me with. I'm using an MSP430G2231 on a LaunchPad development board. I setup the DCOCTL and BSCCTL1 registers to change the DCO clock frequency from the default 1MHz to 10MHz. This worked fine but the clock is jittering badly (viewed on an oscilloscope) and it appears that the clock modulator is causing this even though I turned it off. My code is shown below. Thanks. // Setup DCO to generate 10MHz clock, (RSEL,MOD) = (14,3) BCSCTL1 |= (RSEL1 + RSEL2 + RSEL3); // RSELx = 14 BCSCTL1 &= ~(RSE
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