Part Number:AM3354
The RTC clock behaves strange. On some boards, everything works fine. but on some boards, the RTC clock does not start properly during startup. I does however seem to start if I juggle the RTC_CTRL_REG register a bit.
The RTC in not initialized at startup as we can see.
=> md 44e3e040 1 ; md 44e3e044 1 ; md 44e3e054 1
44e3e040: 00000000 ....
44e3e044: 00000000 ....
44e3e054: 00000010 ....
Now, select internal clock and RUN=1
=> mw 44e3e054 0x40; mw 44e3e040 1;
=> md 44e3e040 1 ; md 44e3e044 1 ; md 44e3e054 1
44e3e040: 00000001 ....
44e3e044: 00000000 ....
44e3e054: 00000040 @...
As we cal see, the RTC_STATUS_REG (44e3e044) is 0 which means the RTC os not running
Fiddle with the RTC_CTRL_REG :
=> mw 44e3e054 50 ; mw 44e3e054 0x40
=> md 44e3e040 1 ; md 44e3e044 1 ; md 44e3e054 1
44e3e040: 00000001 ....
44e3e044: 00000002 ....
44e3e054: 00000040 @...
And now RTC is running! RTC_STATUS_REG = 2
I must be missing something, if someone could give me some useful info about this I would appreciate it.
BR
Andreas
I also posted this, maybe they are related?