AM4379: Boot issues

Lauren Mayfield

Part Number: AM4379

Hi team,

Posting this q on behalf of my customer, please follow-up internally for schematic information to assist with this.

This is a time critical production prototype urgently needed for software development. The power supplies sequence properly. 24MHz oscillator starts. PwrOnRstn (Y23) and WarmRstn (G22) go high. JTAG pod can toggle inputs (no contention). JTAG output (AA24) does nothing. QSPI_CSn (AA18) goes high at powerup no other activity. QSPI_Clk (Y18) stays low. No clock outputs on D24 or C24. The chip was replaced once. No change. We have read SPRS851E, SPRACE0–March 2019 and SPRUHL7H repeatedly and do not see what is incorrect. Relevant schematics attached. Let me know if you need any other information.

Thank you!

over 6 years ago

0 Brad Griffis over 6 years ago

TI__Guru*** 125430 points

Are you able to connect to the board using JTAG? If so, I have developed a script specifically for debugging boot problems. The general procedure for leveraging the script in CCS is described here:

http://git.ti.com/sitara-dss-files/am43xx-dss-files/blobs/master/README

The specific script that you should run is this one:

http://git.ti.com/sitara-dss-files/am43xx-dss-files/blobs/raw/master/am43xx-boot.dss

You will need to save this script to your computer (usually Ctrl-S in most browsers). Sometimes the file extension gets changed during the download. You can rename it to *.dss after you download if needed.

If you are not able to connect via JTAG, there might be a more significant issue. Can you check that TRSTn is pulled low and EMU0 and EMU1 are pulled high? How are the sysboot pins configured? (If you can run the script, this will be scraped from the registers and you simply need to post the resulting output file.)

Best regards,
Brad

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AM4379: Boot issues