The recommended power-on sequence is VCCINT, VCCINT_IO/VCCBRAM /VCCINT_VCU , VCCAUX/VCCAUX_IO, and VCCO to achieve minimum current draw and ensure that the I/Os are 3-stated at power-on. The recommended power-off sequence is the reverse of the power-on sequence. If VCCINT and VCCINT_IO/VCCBRAM have the same recommended voltage levels, they can be powered by the same supply and ramped simultaneously. VCCINT_IO must be connected to VCCBRAM. If VCCAUX/VCCAUX_IO and VCCO have the same recommended voltage levels, they can be powered by the same supply and ramped simultaneously. VCCAUX and VCCAUX_IO must be connected together. VCCADC and VREF can be powered at any time and have no power-up sequencing requirements.
The recommended power-on sequence to achieve minimum current draw for the GTH or GTY transceivers is VCCINT, VMGTAVCC, VMGTAVTT OR VMGTAVCC, VCCINT, VMGTAVTT. There is no recommended sequencing for VMGTVCCAUX. Both VMGTAVCC and VCCINT can be ramped simultaneously. The recommended power-off sequence is the reverse of the power-on sequence to achieve minimum current draw. If these recommended sequences are not met, current drawn from VMGTAVTT can be higher than specifications during power-up and power-down.