MSP-FET: Migrating from msp-fet430uif to the new msp-fet issue

Oh! Just realize the msp-fet works with device it wasn't when I force the MSP430 supply voltage to 3V. 

My MSP430 is supplied to 1.8V on my application. I connected the supply to the MSP-FET pin 4 (voltage sense pin), so, per the datasheet, it should adapt the jtag voltage level to this supply... I let pin 2 disconnected.

Just did more testing and find out it works if I force 1.82V with an external generator but not if I let the 1.81V generated by the 1.8 regulator in the device... Since, the MSP-FET is rated to work at 1.8V why does it fail at 1.81V?

Also, why does it work with the FET430UIF but not with the MSP-FET?

Thank you
M.

Mathieu,

Thank you for posting this question. My first thought here is that CCS v6.1.3 is an old software. Also, MSPFlasher is up to version 3.14. Try updating these to the newest versions and see if this works.

Another question: are you using a TI board or custom made one?

- Travis Black

Hi Mathieu,

Most MSP430 devices (please state which one your project is using) have a supply voltage supervisor that will hold the device in a reset state until it surpasses the required threshold (at most 2 V in some device variants). It is likely that your MSP430 is never exiting the reset condition as can be observed on the RST line. For this reason it is recommended that MSP applications be supplied with 2 V or greater.

Regards,
Ryan

Hi Travis, Ryan,

Travis, I will try to update CCS and MSPFlasher. I'll keep you posted. Please note that I work with a custom made board.

FYI, here is my JTAG pin-out:
1. TDO
2. Not connect (NC)
3. TDI
4. VCC ( 1.8V )
5. TMS
6. (NC)
7. TCK
8. TEST/VPP
9. GND
10. (NC)
11. RST
12. (NC)
13. (NC)
14. (NC)


Ryan, I use the MSP430F5309 in my application. Never encountered boot-up issue at 1.8V. I could say however that I already got some "Can't erase memory..." error in production with the MSP-FET430UIF, but not like with the MSP-FET USB.

Thank you
M.

Hi M,

Your JTAG connections as shown are correct. The MSP-FET has additional functionality built-in (ESD protection, backchannel UART, DC-DC conversion for EnergyTrace measurements) that could be affecting operation at 1.8 V. I will consult the Tools team for further advice or recommendations on this matter. Keep in mind that 1.8 V is the absolute lowest limit of MSP430 operation and any slight voltage dips would be outside of TI's specifications.

Regards,
Ryan

Hi Ryan, 

I agree with you that the MSP-FET doesn't like working at 1.8V.  Please keep me posted with advice from the Tool team. 

In the meantime, I'm working at modifying my jig HW to force a 2.2V during the programming phase.

Thank you

M.

Hi Travis, 

Updating to CSS Version: 7.1.0.00016 did not fix the issue. As discussed with Ryan, I also believe this is more a voltage supply related issue. 

It would be nice to revise the advertising of the MSP-FET and the change the operating voltage specification for 1.85V to 3.6V...

Please let me know if you get any workaround from your discussion with the "Tool" team.

Travis, Ryan, thank you very much for your time and quick replies,

Mathieu

Many thanks!

Please, make sure to adjust the MSP-FET specifications accordingly to prevent false advertising and have other people with this issue.

Have a great day

Hi again Ryan,

As I previously mentioned, to stabilize my jig, I was planning to force 2/2.2V using an external supply for the programming. However, I just realize that the MSP-FET has an internal adjustable supply which can really simplify the fix on the jig since I can disconnect pin 4 and connect pin 2 instead to the VCC supply. I tested it and it works fine!

Using MSPDebug, I figured out to adjust the supply to 2V, but I noticed that each time the msp-fet is connected/disconnected from the computer, it resets the supply voltage to 3.3V (default configuration). Is the default supply voltage configurable? Didn't find out in the documentation...

I'm asking because my board has peripherals with absolute maximum supply voltage of 2.4V and also connected to MSP430 VCC power line. I can then see a risk for these peripherals which I can reduce if I can modify the default voltage applied by the FET at power-up.

Thank you very much!
Mathieu

Hi MAthieu,

As you can see in Table 6 of the MSP Debuggers User's Guide (SLAU647), the MSP-FET VCC_TOOL pin status will be 3.3 V after power up and only change to the desired Target Vcc after communicating such command through JTAG/SBW.

Regards,
Ryan

Ok, thank you confirming this info Ryan.

Have a great day

Mathieu