I made some boards using IMX6D6A(D version) and the boot mode was configured as external parallel Norflash , but one of the boards failed to boot.
Using serial download mode(boot mode[1:0]), can debug in RAM mode, and read SRC_SBMR1 is 00000000, SRC_SBMR2 is 30000001.This is not the right value.
Test power supply, crystal oscillator is OK.The problem persisted after replaced a new CPU.
Could you please help to analyze the reasons for this phenomenon?
for SRC_SBMR1,2 wrong values one can check power-up sequence using
oscilloscope and try to prolong POR duration (just for test up to 1sec.), also
may be recommended to check both crystals (24MHz, 32.768KHz).
As reference please use IMX6DQ6SDLHDG, Hardware Development Guide for i.MX 6Quad, 6Dual, 6DualLite, 6Solo Families of Applic...