Part Number:AM3354
I have a strange problem. I am trying to get the RTC clock running but it does not always start. On some boards it starts fine, no others it does not. I examined the registers in u-boot and found that the initial values(after reset) where different between different boards. how can this be?
In order to better understand what happens, i removed the RTC initialization code from u-boot and booted to a prompt. This is what I got.
Board 1:
=> md 44e3e040 1 ; md 44e3e044 1 ; md 44e3e054 1
44e3e040: 00000040 @...
44e3e044: 00000000 ....
44e3e054: 00000010 ....
As you can see, the RTC_CTRL_REG(44e3e040) register as bit 6 set to 1 which is RTC_DISABLE. And according to the documentation , clearing this bit result in unexpected behaviour, RTC_CTRL_REG should be 0 on reset.
Board 2:
Using the same bootloader as for board 1 I get
=> md 44e3e040 1 ; md 44e3e044 1 ; md 44e3e054 1
44e3e040: 00000000 ....
44e3e044: 00000000 ....
44e3e054: 00000010 ....
This is as expected. All values according to the specs.
I would appreciate any comments that could help me understand this.
I use U-Boot 2017.01 with some patches
CPU : AM335X-GP rev 2.1
BR
Andreas
