General
Review and verify the following for the custom
schematic design:
- The sections
above, including relevant application notes and FAQ
links.
- Pin connectivity
requirements, pin attributes, and signal description.
- Standards
referenced in the electrical characteristics including
recommended operating conditions and any additional
available information.
- IO buffer type
implemented and the allowed supply configuration (LVCMOS
fixed (1.8V / 3.3V) or SDIO dynamic voltage switching).
- Connection of
valid supply to all the IO supply groups (VDDSHVx,
VDDSHV_MCU, and VDDSHV_CANUART).
- Sequencing of the
IO supply.
- 3.3V IO supply
connection.
Schematic Review
Follow the list below for the custom schematic
design:
- Attached device
IO supply and the IO supply group (IO supply rail)
referenced by the interface signals are connected to the
same supply source.
- Pullups are
connected to the same supply rail that is connected to the
processor IO supply group VDDSHVx and attached device.
- Connecting the
3.3V supply connected to the PMIC input directly to the IO
supply groups (processor IO supplies VDDSHVx) is not
recommended since the IO supply is available for an
undefined time in case the PMIC does not start-up and
generate the other processor supply rails.
Additional
- Note the power sequencing requirements based on
the IO supply rail voltage level used.
- Dynamic voltage scaling is supported by some
specific IO supply groups (VDDSHV5 and VDDSHV6 based on the
processor family).
- Dynamic scaling of the IO group supply referenced
to LVCMOS IO buffers is not allowed or recommended
(VDDSHV0..3, VDDSHV_MCU, VDDSHV_CANUART).