I am developing a bare metal system and need to know the board design pretty well to proceed. I have been referring to the OMAP technical reference (spruf98p) and the beagle board technical reference (c3) - I have the c3 board.
The spruf98p mentions in section 18.2.3 that the I2C4 is used to interface between the power management chip and the OMAP. However, section 8.4.2 of the Beagle board technical reference mentions that I2C_0 is used to control the TPS65950. This seems contradictory. Moreover, I do not find any mention of the I2C4 registers in section 18.6.2 of the spruf98p or any other section. Also, the spruf98p numbers I2C from 1 through 3 while the beagleboard technical reference numbers refer to an I2C0. I assume I2C0 (beagle) = I2C1 (OMAP). Did I get this correct?
My best source of information seems to be to reverse engineer the x-loader source code than any technical docs! Please tell me if I have missed something here? What am I overlooking?
I am developing a bare metal system and need to know the board design pretty
well to proceed. I have been referring to the OMAP technical reference
(spruf98p) and the beagle board technical reference (c3) - I have the c3
board.
I would also look very closely at the actual schematic. If you do, you
will see that I2C4 is connected to the power part of the TPS65950 and
I2C1 is connected to the control part of the TPS65950.
The spruf98p mentions in section 18.2.3 that the I2C4 is used to interface
between the power management chip and the OMAP. However, section 8.4.2 of
the Beagle board technical reference mentions that I2C_0 is used to control
the TPS65950. This seems contradictory. Moreover, I do not find any mention
of the I2C4 registers in section 18.6.2 of the spruf98p or any other
section. Also, the spruf98p numbers I2C from 1 through 3 while the
beagleboard technical reference numbers refer to an I2C0. I assume I2C0
(beagle) = I2C1 (OMAP). Did I get this correct?
Page 2789 of spru98p mentions three I2C ports (I2C1, I2C2, I2C3) and
that the fourth I2C port is described in chapter 4 - see section 4.3.3
on page 254.
My best source of information seems to be to reverse engineer the x-loader
source code than any technical docs! Please tell me if I have missed
something here? What am I overlooking?
There are TWO I2C ports that are used to communicate from the processor to the TPS65950. They number either 0-3 or 1-4. Port 0(1) is the main control channel. Port 3(4) is used for smart reflex. There is no contradiction. Feel free to also read the information on the TPS659550 and look at the schematics, as you may find them helpful as well.