mpc5121e-Real Time Clock

Terren Chow terren.chow at gmail.com
Thu Apr 15 04:08:27 EST 2010


I don't think the internal RTC is workable. I've read the RTC section in the
MPC5121 data sheet, and I found that the RTC only keep the time tick
register using VBAT. So if there is a power failure, the RTC will lost its
minute and hour information. After the system boot up, the kernel will read
the RTC to get its wall time, so the system time will reset to 1970xxxxx. I
think there is a design mistake of the CPU.
The only solution is using the mt41 RTC chip on the ADS5121 board as the RTC
device.

-- 
Terren Chow
Graduate student
College of Informatics, SCAU
MSN: terren.chow at hotmail.com
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