Hi,
A customer using our OMAP3530 EVM with TPS65950 onboard, found that the battery backup mechanism is not working well. Evidently the backup status register has not the right value when booting after going to BACKUP state.
- Ideas? Please advice. Thanks.
/Magnus
First questions:
- How long time does it take the TSP65950 to enter BACKUP state ?
- Is MBCHG interrupt nessary for the TPS65950 to enter BACKUP state?
My response:
Second questions:
"When I cut the power, and wait some time, then power up again, I find:
Register bit STS_BOOT BACKUP is always zero and the RTC is not running.
BACKUP_REG_(A..H) is always zero.
SECURED_REG_(A..U) has sometimes the values I put into them, sometimes zero.
We have testet the RTC on the linux, that the EVM board has on board at delivery, and found the RTC is not running when power is removed.
The WinCE BSP to the EVM board (rev G) does not switch on the charger for the backup battery, I have done that and the voltage is now 2V9.
I have scaned the BSP code and found no reference to STS_BOOT,
to me this indicates that the BSP is not finished on this subject. What else is missing?
I have put my "detector" in the RTC startup code, it is run when Windows is starting, prior to this the XLDR bootloader and the EBOOT bootloader
has run, in the bootloaders I have not found any code accessing RTC or BACKUP registers.
What do I miss?"
/Magnus