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 Fixed-voltage
supply for general IO (VDDS0, VDDS1), WKUP and RTC IO group
- ROC, voltage sequence as per
processor-specific data sheet and slew rate requirements for processor fixed
voltage supply for IO groups
- Addition of the required bulk
and decoupling capacitors for fixed voltage supply IO groups
Schematic Review
Follow the below list for the custom
schematic design:
- All IO supply rails for IO
groups have a valid supply connected, irrespective of the use of the
IOs
- Supply rails connected follow
the processor ROC
- Supply levels of the IOs
matches VDDS0, VDDS1, VDDS_WKUP, VDDS_RTC fixed voltage supply for IO
groups
- Slew rate requirements are
followed as per the processor requirements
- Power sequence
recommendations as per the processor-specific data sheet are followed
Additional
- All IOs referenced to the VDDS0, VDDS1, VDDS_WKUP, VDDS_RTC are required to
operate at 1.8V IO level
- A number of processor IOs are not
fail-safe. Applying input voltage to the IOs while the corresponding VDDS0,
VDDS1, VDDS_WKUP, VDDS_RTC supplies are off is not recommended or allowed.
- The recommendation is to verify
all IO pins on each VDDS0, VDDS1, VDDS_WKUP, VDDS_RTC only connects to 1.8V
voltage level.
- The recommendation is to follow
the processor-specific EVM for implementation for adding ferrites and
capacitors
- Leaving VDDS0, VDDS1, VDDS_WKUP,
VDDS_RTC rails unconnected is not recommended. The recommendation is to connect
the power pins to 1.8V.