Figure 6-5 describes the device power-up sequencing.
- VSYS represents the name of a supply which sources power to the
entire system. This supply is expected to be a pre-regulated supply that sources
power management devices which source all other supplies.
- VMON_VSYS input is used to monitor VSYS via an external resistor
divider circuit. For more information, see Section 8.2.4, System Power Supply Monitor Design Guidelines.
- VDDSHV_MCU and VDDSHVx [x=0-5] are dual voltage IO supplies
which can be operated at 1.8V or 3.3V depending on the application requirements.
When any of the VDDSHV_MCU or VDDSHVx [x=0-5] IO supplies are operating at 3.3V,
they shall be ramped up with other 3.3V supplies during the 3.3V ramp period
defined by this waveform.
- The VMON_3P3_MCU and VMON_3P3_SOC inputs are used to monitor
supply voltage and shall be connected to the respective 3.3V supply source.
- VDDSHV_MCU and VDDSHVx [x=0-5] are dual voltage IO supplies
which can be operated at 1.8V or 3.3V depending on the application requirements.
When any of the VDDSHV_MCU or VDDSHVx [x=0-5] IO supplies are operating at 1.8V,
they shall be ramped up with other 1.8V supplies during the 1.8V ramp period
defined by this waveform.
- The VMON_1P8_MCU and VMON_1P8_SOC inputs are used to monitor
supply voltage and shall be connected to the respective 1.8V supply source.
- VDDS_DDR and VDDS_DDR_C are expected to be powered by the same
source such that they ramp together.
- VDD_CORE can be operated at 0.75V or 0.85V. When VDD_CORE is
operating at 0.75V, it shall be ramped up prior to all 0.85V supplies as shown
in this waveform.
- VDD_CORE can be operated at 0.75V or 0.85V. When VDD_CORE is
operating at 0.85V, it shall be ramped up with other 0.85V supplies during the
0.85V ramp period defined by this waveform.
- The potential applied to VDDR_CORE must
never be greater than the potential applied to VDD_CORE + 0.18V during power-up
or power-down. This requires VDD_CORE to ramp up before and ramp down after
VDDR_CORE when VDD_CORE is operating at 0.75V. VDD_CORE does not have any ramp
requirements beyond the one defined for VDDR_CORE. VDD_CORE and VDDR_CORE are
expected to be powered by the same source so they ramp together when VDD_CORE is
operating at 0.85V.
- VPP is the 1.8V eFuse programming supply, which shall be left
floating (HiZ) or grounded during power-up/down sequences and during normal
device operation. This supply shall only be sourced while programming
eFuse.
- VDDSHV5 was designed to support
power-up, power-down, or dynamic voltage change without any dependency on other
power rails. This capability is required to support UHS-I SD Cards.