MSP-FET: How much is MSP-FET Emulation Tool "sensitive electronic"?

HI Luigi,

In some cases it might not be the FET tool, rather the MCU. On MSP430s, there is a recommended R and C placed on the reset line to prevent noise glitches from disturbing the internal reset circuitry.

Do you see this behavior when the FET is disconnected and the MCU is running the code in normal active mode?
What device are you debugging?
Are you using the standard flat ribbon cable that connects directly to the FET tool or are you attaching the FET to your PCB with long, loose wires?

Hi Dennis 

thank you for your prompt Reply

we use the MSP from long time approxmatly 15 year. 

we Always had this problem on all controller that we used  example 

Msp430F435,  Msp430F135,  Msp430F133,Msp430g2955,Msp430g2553,Msp430Fr5972,Msp430g2402  etc..   

we have on the reset pin the R C circuit that is raccomended from TI but the problem is really troublesome 

in any case is impossible to make the debug is Always blocked. 

we triyed also to make shild on the cable probe connected to ground or grounding  but noting is changed.
when this problem happens all is stopped, to test my system I must  disconnect the fet and test the board  stand alone

we use the Flat cable that is into the mspFEt kit  we tried to use like standard lenght and also cutting at the half lenght of the standard
but nothing happens.

we used also the same system of freescale USb Multilink of PE micro for free scale controler and never had this kind of problem

Best Regards 

Luigi 

 

Hi Luigi,

Ok, let me check with our tools team to see if they have any recommendations that might help.

hi Dennis 

have you checked ? 

have you some solution? 

Luigi 

Hi Luigi,

So far no. Let me check again on this.

Hi Luigi,

Just to confirm a few things for our tools team:

1. You only see this behavior when the FET tool is connected and running debug mode?

2. If you terminate debug mode, reset the MCU but the FET tool is still connected to the target you do not see this issue? or only after you completely detach the FET tool?

3. The power strip that is being turned on/off, what is the approximate distance between the power strip and the FET tool when you see this behavior?

4. Does the power strip supply power to any device, appliance that is somehow connected to the circuit you are debugging?

5. What devices or appliances are plugged into this power strip? Motors, florescent lights, etc.?

6 If you move the power strip away from the FET, does the problem stop?

7. Is the power strip on the same AC line as the host computer that is running the FET tool?

8. If the host computer is a desktop PC, what happens if you use a laptop instead that is operating on battery?

9. Is the FET tool that you are using one of the older (grey box) or new (black box)? You can see by looking at the serial number - what is yours?

Hi Luigi,

It's been a couple of days and wondered if you have had a chance to review the questions from our tools team?

Good Morning Dennis,

I'm realy sorry for my late reply, but Luigi was away for a job travel and I couldn't have the possibility to check this email box until today...

However, let's answer to some of your questions.

1. Yes, I confirm the FET tool has this behaviour ONLY when it is connected and running in DEBUG mode.

2. Yes, I don't see this issue if I reset the MCU (with the FET tool still connected)

3. The power strip I referred to in the first post is approximately 20 cm far from the board. What I want to highlight is that we also have the issue if on the board there is a relay (or some relays).

4. No, it doesn't. I noticed this issue the first time while Luigi was testing some other boards. When he switched on/off the power strip nearby my board, while I was doing the debug, the program stopped and I'd had to stop my work and reset the MCU.

5. Essentially other boards we designed.

6. I have to try if moving the power strip this would stop this behaviour.

7/8. PC are dekstop ones, so they are AC connected. The strip is not necessarily connected to the same line. (We tried both the setup).

9. We use the new one. Texas Instruments MSP-FET Flash Emulation Tool black (serial 170500362).

I hope these infos woul help the tools team to find the root of the problem.

Thank you very much & Kind Regards,

Maria Angela

Thanks Maria,

Let me check with our tools team.

Hi Maria and Luigi,

Our tools team is asking the following:

"Can we get more information on how everything is powered? Particularly if the MCU is powered through the MSP-FET or from a separate power supply. Also, how are the power supplies for everything connected, i.e. PC and MCU power supply (if applicable) in one power outlet and the power strip on a different outlet. The underlying question here is if there is any way the power setup could be forming a ground loop. The question on the forums about running the MSP-FET from a laptop that is running on battery is a good test, particularly if the MSP430 is powered from the MSP-FET and not a separate power supply."

Either a detailed description or diagram would be helpful.

Good Morning Dennis.

Thanks for your ready reply.

Luigi today told me that he already tried with a laptop running on battery, but, if there are some relays on the board, the issue persist, regardless of the fact every relay is filtered (on the pin there is an anti-disturbance filter).

However I attached you an example diagram of our setup. Consider that we tried both the configuration with PC and the external power supply with battery or linked to the line. Unfortunately the result doesn't change.

We still have this issue of high sensitive electronic.

Schema.pdf

I hope these information would help to find the problem's root.

Kind regards,

Maria Angela  

 

Hi Maria and Luigi,

It's starting to sound as if this is a radiated noise issue that are affecting the TST or RST line on the MSP, or there is ground bounce disturbance.
Can you scope the JTAG TST and RST pins on the MSP with the debugger attached and see if you can capture any noise spike when the relays are activated?

Also, can you tell me more about how the MSPFET tool connects to the target PCB? Specifically, how is the PCB routing from the connection to the MSP. In other words, are the RST and TST traces surrounded by other signal traces or solid ground plane, or nothing nearby, etc? Also the ground connection where the MSPFET connects to the PCB, is it directly connected to a ground plane or only a ground trace that ties somewhere else to a ground plane?

Good Morning Dennis,

I completely agree with you: I expect there is some noise on TST/RST pins for the JTAG wire.

But the question is: how can I protect my board, during debug, from this disturbance?

At the moment, unfortunately, I'm not able to scope the JTAG pins as you mentioned, but I'm pretty sure the issue is related to this noise, I imagine, there would be on JTAG wire ( I suppose it because when I disconnect the FET everything works well).

The issue however shows up not only on boards where there are some relays, but also on other different boards. I think the PCB is pretty strong against electromagnetic disturbance because this is the first time there is an issue like this in many years. In addition, as I said before, every boards works fine without the FET connected.

Moreover, on some boards there are multiple MCU, not only TI but also Freescale Semiconductor. In this case, if I debug the program with the USB Multilink Interface by Freescale (older thanMSP-FET) I haven't any trouble, while, on the other hand, with MSP-FET I couldn't be able to finish my debug session.

If it is possibel I would ask you to leave an external email address where I could send you some photos and also some electrical schemes, so that you could have a better overview of the issue, I hope.

Many thanks and my kindest regards,

Luigi

HI Luigi,

Done. I sent you a message with my email.