TPS6594EVM: TPS6594EVM

Hello Rocky,

so you are correct with the register LDO2_CTRL (0x1E), the LDO2_SLOW_RAMP is a bit field in the register specifically position 1 out of the 8 possible bits [7:0].

rocky rocky said:

I want to set TPS6594EVM "LDO-2 SLOW RAMP" as 3mv/us, but I don't find which register can be set in the datasheet for "LDO2_CTRL", could you tell me which register can I set?

To set it in the GUI while it is up and running you can go to the register page in the GUI, go to the address 0x1E and flip the bit.

Now that only changes it after it boots up and if the power goes off then it is not saved, if you would like this to be the default behavior upon boot up you need to go through the NVM configuration like you have in your post.

rocky rocky said:

and I want to set by the GUI, it is still fail.  but if I change "LDO2 VOUT" voltage from 1.25V to 2.7V, it is ok. just like only SLOW RAMP register can not be set.

Are you trying to change the settings in this screen and see the changes done from the device?

If so my apologies, this screen is reserved for changing the boot up configuration (NVM), to change the settings after boot up you, you need either use the quick start settings (thunderbolt on the left side of the screen) or the register settings page (pencil on the left side of the screen).

Hope that helps,

Nicholas

rocky rocky said:

yes, I according to you suggestion, and change my .json file

The changes on the .json should be made through the generation on the GUI. Please do not try to directly change the file through an editor.

I understand you have the other thread and there is confusion as what the device is doing and the GUI.

Ultimately, the GUI is a tool that allows for a much more easily configurable experience for the default boot up settings and defining the transition behavior.

Here are the three documents that detail the interaction between the GUI, boot settings, and the all other things regarding the TPS6594

1. TPS6594-Q1 Power Management IC (PMIC) for Processors with 5 Bucks and 4 LDOs datasheet (Rev. B)
2. Scalable PMIC's GUI User’s Guide (Rev. B)
3. Scalable PMIC NVM Update Guide (Rev. A)

Below is the condensed information of what is going on.

The TPS6594 has default boot settings (NVM) this is code that is in the memory on the device. These set the default voltage levels for the output of the device and how the device reacts to certain events like a shortage. These are loaded into the registers after the device receives sufficient power and is explained further in 1 in the above. 3 details what registers are configurable for these default settings.

Now after the default values are loaded into the registers, the user can change them from these default values in the form of IIC (I2C) or SPI writes.

The GUI tries to make these process of defining the boot settings much easier and the .json file is saved file that corresponds to the choices the user makes, through this file the GUI generates assembly and binary files which are used to flash the onboard memory on the TPS6594. The .json file is only used in this process and does not make changes while the device is up and running.

The EVM has a microcontroller onboard and is responsible to speaking to the MCU via I2C or SPI, this communication gets relayed through MCU to the computer running the GUI. So any of the registers you see on the GUI may not be reflective on what is going on the device, the MCU needs to read the device and the same thing for writes. To make the changes after the device has booted up, you go to the pencil in the GUI, but more details on how to use the GUI is in 2.

Hope that helps,

Nicholas