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TPS65910A (PMIC) Registers Configuration for AM3354 Processor

Sarusha Narayan
Prodigy 125 points
Other Parts Discussed in Thread: TPS65910A, AM3354, TPS65910

Hi,

TPS65910A (PMIC) Registers Configuration for AM3354 Processor

Kindly check my below understanding :

1.TPS65910A contains an internal EEPROM containing configuration registers.

2.These registers can be configured through I2C (2 No) interface and configurable GPIO interface.

3.USB to GPIO converter was used in Evaluation Module for configuration.

4.The sofware is a simple graphical user interface (GUI) that simplifies registers
access for the IC.

5.Usage of TPS65910A for powering DDR3 will be taken care by the configuration registers.

Kindly let me know whether my understanding is right?

How exactly can the IC(TPS65910A) be configured for required voltages from its default state ?  (any alternate ways?)

More information on the availibility and usage of software ?

Regards,

Sarusha Narayan.

  • 0
    TI__Intellectual 1820 points

    Hello,

    1. That's right. The EEPROM configuration can be found in TPS65910Ax User's Guide For AM335x Processors (SWCU093A).

    2. You can access these registers by I2C interface (except the time slot value). The default value of these registers will be the one of the EEPROM configuration when booting with boot1boot0=[10]

    3. I do not follow your point, could you please specify it ? Please refer to " Using the TPS65910 EVM, A Multichannel Power-management IC, 3 Buck, 1 Boost, and 8

    LDOs " (SWCU065E)

    4. The software is indeed a GUI.

    5. For powering DDR3, you will need to use TPS65910A3, for powering DDR2, please use TPS65910A. As described p3 of the TPS65910Ax User's Guide For AM335x Processors (SWCU093A).

    If you want to change the voltage, you can do it by I2C access. However, the power up sequence will be the one defined in the EEPROM configuration.

    Best regards,

    Flore

  • 0 in reply to Flore Auzanneau
    Prodigy 200 points

    Hello,

    going further in the TPS65910's behavior, is it possible to configure the power supplies output voltages via I2C previous to letting them power up? I need to do that because I need to use in my system a configuration that is different from the one available by default.

    I mean, is it possible to use the I2C communication while you hold the PWRHOLD pin HIGH, for example? I'm afraid I'll have voltage different from the desired on the outputs while I'm still configuring the PMIC via I2C. (This I2C wouldn't be controlled by the AM335x, but by a microcontroller with an independent power supply which would also supply the VDDIO pin of the TPS65910).

    Thanks for the help.

    Best regards,

    Breno Rocha.

  • 0 in reply to Breno Rocha
    Prodigy 200 points

    Hello,

    complementing the question, would it be troublesome to change the VDD_MPU voltage from 1,1V to 1,2V after the boot sequence is finished (considering the AM335x in the ZCZ version operating at the OPP120)? That's the voltage that is different from the TPS65910 EEPROM boot we're probably using (TPS65910AA1).

    Best regards,

    Breno Rocha.

    ps.: This complement of the question is more related to the processor, so if it's not the right place, please move it to the proper place. 

  • 0 in reply to Breno Rocha
    TI__Intellectual 1820 points

    Hello,

    For each OFF to ACTIVE transition, resources will take default values configured in the EEPROM. It is not possible to configure the power supplies output voltages via I2C previous to letting them power up.

    If you hold PWRHOLD pin HIGH when in OFF state, it will launch the switch on sequence if there is no gating conditions (OFF to ACTIVE transition).

    For AM335x questions, please ask on http://e2e.ti.com/support/dsp/sitara_arm174_microprocessors/f/791.aspx

    Best regards,

    Flore

  • 0 in reply to Flore Auzanneau
    Prodigy 200 points

    Hello, Flore,

    thanks for the reply. Considering what you said, there's no way of changing the voltage previous to turning the processor on (without using extra external components), so we're going to use the following strategy, adapted from another topic (http://e2e.ti.com/support/dsp/sitara_arm174_microprocessors/f/791/p/214814/758140.aspx#758140):

    1. Boot AM335x by TPS65910 with the default setting (VDD_MPU=1.1V);

    2. After booting in OPP100 mode, change the register of TPS65910 so that it can provide the desired voltage (1.2V) to VDD_MPU;

    3. Configure the AM335x ARM (A8) frequency in the processor;

    4. The above procedures shall be repeated every time the system power goes from an OFF to an ON state.

    I haven't tested yet, but I believe that works.

    Thanks again for the help.

    Best regards,

    Breno.