Table 6-7, Figure 6-10, Figure 6-11, and Figure 6-12 define device power requirements when using RTC + IO + DDR low-power mode.
Table 6-7 RTC + IO + DDR Low-Power Mode Sequencing –
Supply / Signal Assignments See: Figure 6-7, Figure 6-8, and Figure 6-9
| WAVEFORM |
SUPPLY /
SIGNAL NAME |
| A |
System
power |
| B |
VDDSHV0(1), VDDSHV1(1), VDDA_3P3_USB |
| C |
VDDSHV0(2), VDDSHV1(2), VDDS_OSC0(3), VDDA_PLL0(3), VDDA_PLL1(3), VDDS_WKUP, VDDS0, VDDS1,
VDDA_ADC(3), VDDA_1P8_DSI(3), VDDA_1P8_USB(3), VDDS_RTC(4) |
| D |
VDDA_3P3_SDIO(5)(6), VDDSHV2(5), VDDSHV3(5), VDDSHV4(5) |
| E |
VDD_RTC(7) |
| F |
RTC_PORz(8) |
| G |
VDDS_DDR(9) |
| H |
VDD_CORE(10), VDDA_CORE_DSI(11), VDDA_CORE_DSI_CLK(11), VDDA_CORE_USB(11), VDDA_DDR_PLL0(11) |
| I |
WKUP_OSC0_XI,
WKUP_OSC0_XO |
| J |
PORz |
| K |
PMIC_LPM_EN0(12) |
(1) VDDSHV0 and VDDSHV1 are dual voltage IO
supplies which can be operated at 1.8V or 3.3V depending on the application requirements.
When any of the VDDSHVx [x=0-1] IO supplies are operating at 3.3V, they shall be ramped
down with other 3.3V supplies during the 3.3V ramp period defined by this waveform.
(2) VDDSHV0 and VDDSHV1 are dual voltage IO
supplies which can be operated at 1.8V or 3.3V depending on the application requirements.
When any of the VDDSHVx [x=0-1] IO supplies are operating at 1.8V, they shall be ramped
down with other 1.8V supplies during the 1.8V ramp period defined by this waveform.
(3) VDDS_OSC0, VDDA_PLL0, VDDA_PLL1,
VDDA_ADC, VDDA_1P8_DSI, and VDDA_1P8_USB may be powered off when entering RTC + IO + DDR
low-power mode to conserve power.
(4) VDDS_RTC must be sourced from an always
on power source when using RTC + IO + DDR low-power mode.
(5) VDDA_3P3_SDIO was designed to support
power-up or power-down without any dependency on other power rails. VDDSHV2, VDDSHV3, and
VDDSHV4 were 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.
(6) VDDA_3P3_SDIO is the 3.3V power rail for
the internal SDIO_LDO. This power rail must be sourced from the same 3.3V power supply
that provides power to a UHS-I SD Card connected to MMC1, which allows the MMC1 IOs and
the SD Card IOs to power-up and power-down at the same time when the SD Card power supply
is powered off to reset the SD Card. For this use case the SDIO_LDO output
(CAP_VDDSHV_MMC) is used to power the VDDSHV3 IO power rail, which will ramp-up and
ramp-down along with the VDDA_3P3_SDIO power rail.
(7) VDD_RTC must be sourced from an always on power source when using RTC + IO + DDR
low-power mode.
(8) RTC_PORz can be released once the VDDS_RTC and
VDD_RTC power rails are valid.
(9) VDDS_DDR does not have any specific power
sequence requirement, but the JEDEC standard for DDR devices requires the potential
applied to its VDD1 power rail to always be greater than the potential applied
to its VDD2 power rail during the power-up and power-down sequences.
(10) The potential applied to VDD_CORE must
never be greater than the potential applied to VDD_RTC + 0.18V during power-up or
power-down. This requires VDD_RTC to ramp up before and ramp down after VDD_CORE.
(11) VDDA_CORE_DSI, VDDA_CORE_DSI_CLK, VDDA_CORE_USB, and VDDA_DDR_PLL0 shall be sourced from
the same power source as VDD_CORE. Care should be taken to ensure that voltage
differential between VDD_CORE and VDDA_CORE_USB is within +/- 1%.
(12) PMIC_LPM_EN0 is pulled high with a weak
internal pull-up while RTC_PORz is asserted. The weak internal pull-up is turned off and
PMIC_LPM_EN0 is driven high on the rising edge of RTC_PORz. The RTC module can be
configured to drive PMIC_LPM_EN0 low to enter RTC + IO + DDR low-power mode and drive
PMIC_LPM_EN0 high to exit RTC + IO + DDR low-power mode, such that PMIC_LPM_EN0 can be
used to cycle power on/off to VDD_CORE and all 1.8V analog power rails.