Hi,
I have intermittent boot up issues on my RT1176 custom board.
Initially, it was an intermittent power issue where the internal DCDC does not always start up and the PMIC_ON_REQ remains deasserted. Thereafter, I found out that the DCDC_PSWITCH delay is slightly less than 1ms. Hence, I increased the resistance of the RC delay from 30K to 100K and managed to get the board's DCDC to start up consistently where PMIC_ON_REQ got asserted without fail.
However, the board does not always boot up from the octal flash. If the board power cycle from OFF to ON within 2 seconds, there is no problem. But if the board power is OFF for more than 2 seconds, it may or may not boot up.
When the board boots up, the DCDC_ANA is 1.78V and DCDC_DIG is 1.09V.
When it is not booting up, the DCDC_ANA is 1.78V and DCDC_DIG is 0.98V.
Would greatly appreciate any guidance on what I should check.