MSP430F1491: Release Binary Packaging Guidance

Hello Balley,

So you want to know how to generate .bin file of the bootloader project and the application project through IAR, right?

Best Regards,

Janz Bai

Correct

It looks like this project got passed to another team within the company and they have a high priority to address it. Seems to go beyond generating the binaries. See customer response below:

"This is an older product that they updated to replace some obsolete parts but tried to retain as much of the original design as possible to minimize the risk of issues.

Despite their best efforts, they have an issue with the new board.  Intermittently, the MSP430 “doesn’t boot”.  I’m trying to get them to verify whether it comes up with the DCO and then has issues switching to the high-speed oscillator, or if the DCO is having problems.  The team reports that from a completely discharged state (left unpowered for a minute or more), it almost always boots when power is applied.  However, if they take power away for a few seconds and then try to restart the device, the issue is more common.  Also, some boards seem to be more prone to this issue than others.

The design uses a 4MHz  ECS-40-20-5PXDN crystal with 39pF caps across XT2IN/XT2OUT as shown below.

The original design used a 32kHz ECS-.327-12.5-17X crystal on XIN/XOUT.  They tried to use the low frequency oscillator with the 32kHz crystal on the new board, but they experienced the same issues.

 DV_CC (pin 1) and AV_CC (pin 64) are powered by 3V3, each with 1uF and 10000pF caps.

nRST/NMI is pulled low when 3V3 drops below 2.1V by a voltage detector/supervisor with an open-drain output.

They did replace the regulator from the original board with a TPS7A2601DRVR, but the MSP430 shouldn’t tax that regulator at all.

Any thoughts on what may be causing the issue?  Know anyone else who may have some insight into this problem?  I know, I’m not giving you a lot to go on, but any help would be appreciated.

Thanks."

Hello Bailey,

1). It sounds that the original board before they replace some obsolete parts doesn't have issue. After they replace parts, issue occurs. Just to confirm what is different between the original board and the new board, I think the difference is the important point to resolve it.

2). Please check the RST circuit and you can try to monitor the voltage on RST pin when re-powering MCU up after 1). left unpowered for a minute or more; and 2). left unpowered for a few seconds.

3). About the external oscillator and its circuit and related parameters, please refer to the datasheet.

Best Regards,

Janz Bai

For your second question

2). Please check the RST circuit and you can try to monitor the voltage on RST pin when re-powering MCU up after 1). left unpowered for a minute or more; and 2). left unpowered for a few seconds.

 Just curious why the unpowered time would matter if RST gets a clean pulse – is there something that I should be aware of?

Hello Bailey,

I am out of office today, I will reply to you soon

Hello Bailey,

Because the issue occurs on customer side is very strange, I just want to confirm that when you re-power up MCU after unpowered for a few seconds. the RST line will not be pulled-down abnormally for long time, which may cause MCU can't boot.

Best Regards

Janz Bai

Thank you for this. Just so you're aware for future questions, the customer believes they found the problem.  It appears to be due to the 200mV POR issue.  The recommended resistor values for the feedback divider on the TPS7A2601DRVR are too high to quickly bleed the voltage off the bulk capacitance on the rail.  They lowered the resistor values so that the feedback divider more aggressively drains the rail when the regulator is disabled.

Hello Bailey,

I am happy to hear that customer has found the problem. And about the recommended resistor value issue on TPS, I think you can re-create a new post to let TPS team AE to give you some commons.

Best Regards,

Janz Bai