General
Review and verify the following for
the custom schematic design:
- Above sections, 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 below list 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 because 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 are supported by some specific IO supply groups
(VDDSHV4, VDDSHV5 and VDDSHV6 based on the processor family)
- Dynamic scaling of the IO group supply referenced to LVCMOS IO buffers are not
allowed or recommended (VDDSHV0..3, VDDSHV_MCU, VDDSHV_CANUART)