MSP430FW427: The MSP430FW427scanif module does not work properly

Hi,
we will have a look at this issue and come back to you.

Best regards,
Andre

wang jingang said:

1:The non-magnetic water meter made by our company with MSP430FW427 can be measured when it is delivered for inspection. It will not be measured when it is installed with the client in a few days. Close the scanif module (SIFCTL1=0) and open it again, then it will be measured normally.Could you please prove that the ScanIF module is indeed in trouble?

Can you please provide more details about what process(es) the water meter goes through from when it works to when it doesn't? For example, is there a change in supply voltage or is it powered on/off? It sounds like the device hangs. Are you getting any results before closing/re-opening the SCANIF module? There are a few SCANIF errata that could come into play too.

Regards,

James

It seems like this issue could have to do with reset circuitry.  Some things to look at:

1. The voltage detector IC could be sensitive enough that it is detecting and triggering a reset when the scan interface is turned on.  When scan interface is turned on, there will be an inrush current which will drop the voltage.  This may not have been seen in the lab if the boards were used frequently enough and the caps retained some charge.  As a test, you could try removing the voltage detector, adding the reset capacitor, and pull up the reset pin without the use of the voltage detector IC.  See if you still see the same issue in this configuration.

2.  Capacitor C07 should be a low leakage type of capacitor.  This cap could be causing an issue where the voltage drop is too high from the inrush current. 

Hi, Eddie:

Thanks for your reply and suggestion. I will let customer test based on your tips.

And one more question:

"Capacitor C07 should be a low leakage type of capacitor.  This cap could be causing an issue where the voltage drop is too high from the inrush current. "

Is there any detail spec requirement ? Or could you recommend some vendor? Thanks!

Vivian

Hi, Eddie:

Thanks for your reply and suggestion. I am wang jingang's customer.

We add flags to watch PUC or POR, So we can confirmed that the voltage detector IC is not triggering a reset.

We have used MSP430FW427 more than 10 years, It is a good MCU,but We faced a myriad of problems, such as
1.when writing flash, the SIFCNT register will be changed every time.
2.when in DCM processing ,TimerA could not capture signals of the SCANIF module compare some times, so DCM is always failed.
3.Last problem is just as wang jingang says, the SCANIF module stoped working,but another Peripheral device is worked properly。