Hi all,
my new design(V0.2) add a line from CR2030 to PMIC_BBAT,like this:
then,my load board failed to start。 Can’t determine if it’s a core board or a load board problem。but during my debugging,3~4core board start successed,and zhe core board successed once,can success every time(try 100+)。
jectpack 4.6 REV3
sdkm 1.7.2.9007
We have the following questions:
1、Can’t determine if it’s a core board or a load board problem;
if core board,Can’t determine if it’s a core board or a load board problem;
if module board,zhe core board successed once,can success every time。
It is OK without CR2030, right? You should focus on the RTC battery/capacitor and find out why it will cause boot failure. What is the device of the backup battery attached to? What if you cut off the line to that device?
So it is a power sequence issue? Have you compare to the power on sequence as listed in design guide? The key point is to let module power on first and all carrier power supplies should be ON later than module.
SYS_RESET going high means module power on is OK. The carrier supplies should be enabled by SYS_RESET. That can guarantee carrier supplies are turn on later than module.