We have design a custom board with AM3715 and TPS65950, almost the same like Beagleboard XM.
What we see is exactly the power up sequence REGEN-> VIO -> VDD1 -> VDD2 -> VPLL1 -> 32KCLKOUT -> SYSEN -> CLKEN -> HFCLKOUT -> NRESPWRON -> NRESWARM (from OMAP). But we can't boot from MMC because the VDD_MMC1 is always low. I understand, that OMAP should configure the TPS65950 / VDD_MMC1 over I2C, but I2C bus is dead.
We tried to control the TPS65950 over I2c with I2C-Master (AARDVARK) from PC. To do so, we have removed the OMAP. But we din't see a valid I2C-start condition! The I2C_SCL goes low for few us (only one time), I2C_SDA goes low before SCL, but goes high after few ns -- this is wrong. This is not a start condition and looks to me like the TPS65950 drives the I2C_SDA.
1 - I2C_SCL
2 - I2C SDA
The question is, does we have a chance to control a TPS65950 over I2C?
The schematics are the same like beagleboard xm, so if we remove the OMAP we should be able to control the TPS65950 over i2c?
We have the same behavior on 5 boards.
Does have anyone any idea, what we can do?
Konstantin