2.2.1 Requirements

In the section “Recommended Power Supply Sequencing”, in the Electrical Characteristics chapter of the SAM9X7 Series data sheet, refer to the figures “Recommended Power Sequence at Power-Up” and “Recommended Power Sequence at Power-Down” for the applicable power supply sequencing.

The Power-Up Timing Requirements table shows the following:

• VDDBU must be established within 0.2 ms after VDDIN33 is established.
• VDDIN33 must be stable for at least 0.1 ms before the periphery group (VDDIOM, VDDLVDS, VDDQSPI, VDDNF, VDDIOPx) gets established.
• VDDCORE must be established after the periphery group.
• The NRST line must be kept low for at least 8 ms after all other power supplies have become stable.

The Power-Down Timing Requirements table shows the following:

• The NRST line must be pulled low before the power supplies are powered off and there is no specific order and no specific timing required among the channels.