Help with Boot Mode Configuration

[james_carter]

I am having an issue with Boot mode configuration.   I tie Boot_mode_1 to ground and tie Boot_mode_0 to 3V via 4.9k resistor, and the IMX6 Dual/Quad processor still looks at port pins to set configuration - DDR memory configuration is set to the wrong state because I use a pull-up on EIM_A20.  I thought Boot_mode_1 had to be high for this to occur.

Also, if I ground both Boot_mode_0 and Boot_mode_1, my USB does not function even though EMMC has not received programming.

Any help would be much appreciated.

[igorpadykov]

Hi James

one can attach jtag and check SRC_SBMR1,2 registers, described in
sect.60.7.2 SRC Boot Mode Register 1 (SRC_SBMR1).

Reason for wrong boot reading may be hardware, unstable clocks (24MHz, 32.768KHz crystals), 

power supplies ripples, one can check board using i.MX6 System Development User’s Guide

https://www.nxp.com/docs/en/user-guide/IMX6DQ6SDLHDG.pdf

Check if clocks are stable when POR was released, just for test one can try to prolong
POR up to 1.sec.

May be recommended to look on i.MX6Sabre SD schematic and compare it with custom board:

Schematics (1)
i.MX6_SABRE_SDP_DESIGNFILES
http://www.nxp.com/products/software-and-tools/hardware-development-tools/sabre-development-system/s...

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------