I'm looking at how to practically manage RTC calibration with the MSP430FE427. Because this is for a high-volume, low-cost application, I cannot afford to individually "tune" the RTC calibration constant for each unit. So for this to work, I see two possibilities :
1. I understand there is a fairly consistent RTC calibration for devices within the same batch, so is there a way to automatically detect via firmware (or programming hardware) when a new batch of chips is in production? Is there some sort of serial number or batch number within the MSP430FE427 that is accessible to the firmware (or to programming hardware)?
2. Is RTC calibration constant within the device already "tuned" by TI? If so, I could then read this value and apply an offset (determined empirically) to suit the crystal loading conditions for my application.