[gil_he]

Hi Neeraj,

When connecting to the SIP through JTAG:
Can the NVM of the PMIC be programmed via JTAG?
Which SW can be used for that?

thanks
Gil

• This reply was modified 2 years, 10 months ago by gil_he.

[gil_he]

Hi Neeraj,

The situation I described is for a board with the SiP assembled on it.
Default BUCK3 voltage is 3.3V (on first power-up, before any programming) and the connections on the board are as I described (BYPASS_REG1V8 and VDDA1V8_REG pins connect to VDD=3.3V).
So, it will put VDDA1V8_REG in bypass mode and will connect 3.3V (on first power-up), through the VDDA1V8_REG pin, to the USB HS PHY, which is wrong (it should get 1.8V).

Will the guide you referred me to, answer this scenario?

thanks
Gil

• This reply was modified 2 years, 10 months ago by gil_he.

[gil_he]

hello,

Please ignore the first post on this thread and consider the following (I edited the post, but something went wrong):

We will be using the OSD32MP157C-512M-BAA.
The default voltage for BUCK3 and BUCK4 is 3.3V.
I want to change it to 1.8V.
In the design, BYPASS_REG1V8 and VDDA1V8_REG pins connect to VDD, and will get 1.8V.
This is correct for a VDD=1.8V.
However, on first power-up of the system, 3.3V will be present there by default.
This will put VDDA1V8_REG in bypass mode and will connect 3.3V (through the VDDA1V8_REG pin) to the USB HS PHY, which is wrong.

How should I handle this?
BYPASS_REG1V8 will connect to VDD, thus in bypass mode.
VDDA1V8_REG pin will be floating. Thus, VDDA1V8_REG is not powered and USB PLL (in USB HS PHY) will not be get its 1.8V.
VDD3V3_USBHS will be disabled on power-up by default (fulfil the “VDDA1V8_REG must be present before VDD3V3_USBHS” requirement)
BUCK3 will change to 1.8V through the STM and once it is 1.8V, connect VDD to VDDA1V8_REG pin (either power-down the system and do that, or electrically relay VDD to this pin).
Enable VDD3V3_USBHS and change its power-up state to the appropriate rank.

Is that a valid way?

Any better way to do that?

thanks
Gil

[Author]

Posts