J721EXCPXEVM: J721S2XSOMXEVM: Boot Mode Control from Test Automation Header

Moses Christopher Bollavarapu

Part Number: J721EXCPXEVM
Other Parts Discussed in Thread: TCA6424A

Hi,

I would like to check if the boot-mode switches(mcu and sys) could be overridden by using the Test Automation Header?

As per the EVM Common Board Schematics, Section 55, it says bootmode control from test automation header,

But in the Section 56, the test automation header(J50) doesn't really seem to indicate the pins that could be used to manipulate boot modes(except for the TA_BM_IOEXP_RSTn).

Could you kindly confirm if the boot-modes can be set/manipulated using Test Automation Header(J50), if yes, how does J50 pinout look like.

Thank you.

Best,
Moses

over 1 year ago

0 Moses Christopher Bollavarapu over 1 year ago

Prodigy 235 points

In the meantime, I found that this could be controlled via the I2C (PM2).

0 Robert Eschler over 1 year ago in reply to Moses Christopher Bollavarapu

TI__Guru 52335 points

Yes - the test automation header interface can access the on-board IO expanders to driver BOOTMODE pins. Set all dip switches to OFF (recommended). The interface is design to work with an TI internal controller board, but any I2C controller can drive/program the IO expanders.

0 Moses Christopher Bollavarapu over 1 year ago in reply to Robert Eschler

Prodigy 235 points

Hi Robert,

There is a 5pin connector, J12 on the Common Processor Board; could I also use it instead of the Test Automation Header?

Because then I don't have to use a flex cable and an adaptor to just access the I2C lines.

Also, if I understand correctly, I need to control GPIOs from the TCA6424A, but are there any prerequisites ?

Thanks.

+1 Robert Eschler over 1 year ago in reply to Moses Christopher Bollavarapu

TI__Guru 52335 points

Yes should be able to use the header (PM2 I2C bus) to access the TCA6424A devices. As previously mention, likely want to put dip switches in OFF state.

0 Moses Christopher Bollavarapu over 1 year ago in reply to Robert Eschler

Prodigy 235 points

Hi Robert,

I could control the bootmode buffers from the I2C Controller, but the bootmode doesn't seem to be effective, because during the power cycle phase, the I2C Interface lost power, therefore, it took some time to set the bootmode buffers through I2C interface.

How could I disable the reset of I2C Interface, so as to not reset the buffers?
Do I need to make SOC_PORZ_OUT Low?

If yes, how could I access it, from the schematics, I couldn't find any header/TP exposed on the PCB.

Thank you.

0 Moses Christopher Bollavarapu over 1 year ago in reply to Moses Christopher Bollavarapu

Prodigy 235 points

Fixed by syncing the Resets, everything works for now.

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J721EXCPXEVM: J721S2XSOMXEVM: Boot Mode Control from Test Automation Header