6.3.1 Power-On Sequence
The device should be powered-on in the following order:
- RTC (RTC_CVDD) may be powered from an external device (such as a battery) prior to all other supplies being applied or powered-up at the same time as CVDD. If the RTC is not used, RTC_CVDD should be connected to CVDD. RTC_CVDD should not be left unpowered while CVDD is powered.
- Core logic supplies:
- All variable 1.2V - 1.0V core logic supplies (CVDD)
- All static core logic supplies (RVDD, PLL0_VDDA, PLL1_VDDA, USB_CVDD). If voltage scaling is not used on the device, groups 2a) and 2b) can be controlled from the same power supply and powered up together.
- All static 1.8V IO supplies (DVDD18, DDR_DVDD18, and USB0_VDDA18 ) and any of the LVCMOS IO supply groups used at 1.8V nominal (DVDD3318_A, DVDD3318_B, or DVDD3318_C).
- LVCMOS IO supply groups used at 3.3V nominal (DVDD3318_A, DVDD3318_B, or DVDD3318_C).
There is no specific required voltage ramp rate for any of the supplies as long as the LVCMOS supplies operated at 3.3V (DVDD3318_A, DVDD3318_B, or DVDD3318_C) never exceed the STATIC 1.8V supplies by more than 2 volts.
RESET must be maintained active until all power supplies have reached their nominal values.