Hello,
In the datasheet P.53 9.1.2, there is the discription of "the VDDIO supply needs to reach the expected operating voltage (1.8 V or 3.3 V) before the other supplies (VDDn) begin to ramp.".
I understood that we must ramp up the VDDIO supply at first , if we use 1.8V power supply only.
Could you please let me know the reason that why the VDDIO supply needs to reach the expected operating voltage before the other supplies begin to ramp even so VDDIO is 1.8V?
Also, could you please let me know the timing requirement of power up sequence?
I understood that the order but there is no timing requirement.
Best Regards,
Ryuji Asaak