General
Review and verify the following for the custom
schematic design:
- Reviewed above "Common checklist for all sections" section of the
user's guide.
- Connection of VDD_CANUART and VDDSHV_CANUART supplies to implement partial
IO low power mode functionality.
- Connection of VDD_CANUART and VDDSHV_CANUART in case partial IO low power
mode functionality is not implemented.
- VDD_CANUART operating voltage requirement with respect to VDD_CORE.
- ROC, slew rate and voltage sequence requirements for VDDSHV_CANUART and
VDD_CANUART.
Schematic Review
Follow the below list for the custom
schematic design:
- VDDSHV_CANUART and VDD_CANUART supplies are available before the other processor
supplies are available, when partial IO low power mode functionality is
implemented.
- The recommendation is to connect VDD_CANUART and VDDSHV_CANUART to an always-on
power source when implementing partial IO low power mode.
- Voltage rails (levels) connected
to VDDSHV_CANUART and VDD_CANUART follow the ROC and slew rate requirements as
per the processor-specific data sheet.
- When VDD_CANUART is connected to an always-on power source, the recommendation
is to never apply a potential to VDD_CORE which is greater than the potential
applied to VDD_CANUART + 0.18V during power-up or power-down.
- Partial IO low power mode requires VDD_CANUART to ramp up before and ramp down
after VDD_CORE.
- VDD_CANUART and VDD_CORE operating voltage does not have any dependency (can
operate at different core voltages).
- The recommendation is to connect VDDSHV_CANUART to a valid 1.8V or 3.3V IO
supply source in case partial IO low power mode is not implemented.
- VDDSHV_CANUART and VDD_CANUART follow the recommended power sequence when
partial IO low power mode functionality is not used.
- The recommendation is to connect VDD_CANUART to the same power source as
VDD_CORE, VDDA_CORE_CSIRX0, VDDA_CORE_USB, and VDDA_DDR_PLL0 in case partial IO
low power mode is not implemented.
Additional
- The recommendation is to verify the IO level compatibility between the processor
inputs and the inputs connected from the attached devices (wakeup source).
- Partial IO mode
functionality: Processor circuit sections related to partial IO
functionality are disabled when power is applied to the processor (for the first
time, cold reset). When partial IO circuits are disabled, the MCU_PORz input
signal propagates to the circuits implementing partial IO functionality. The
MCU_PORz input signal is blocked from the circuits implementing partial IO
functionality after the software enables the partial IO functionality (circuits)
and configures the processor to monitor wakeup inputs. This is necessary since
the MCU_PORz input signal is asserted by the PMIC when the signal begins the
power-down sequence associated with the other processor power rails.