General
Review and verify the following for
the custom schematic design:
- Above section including
relevant application notes and FAQ links
- Pin attributes and signal
description
- Electrical characteristics,
timing parameters and any additional available information
- Interface configuration and
recommended connections (including IOSET)
- Series resistor (22Ω) added
to the clock outputs near to the processor clock output pin
- Parallel pull (pulldown for
attached device clock input) added for any of the processor or attached IOs
that can float
- Performance and signal integrity related concerns
have been analyzed (simulated) when connecting to
multiple attached devices
- Provision for series
resistors added for all the interface signals to minimize reflections or
isolate for testing
- Configuration of SPI data D0 and SPI data D1 bits
(data direction)
Schematic Review
Follow the below list for the custom
schematic design:
- Pullup values used (10kΩ or similar)
- Series resistor value used (22Ω) and the
placement (near to processor clock output pin)
- Pullup referenced to the processor VDDSHVx or
VDDSx for corresponding MCSPI instance and pins
- Processor VDDSHVx or VDDSx and the attached
device IO supply are sourced from the same
supply
- Supply rails connected follow
the ROC
Additional
- Verify fail-safe operation when connected
external interface connector (carrier or add-on board).
Applying an external input before supply ramps can cause
voltage feed and can affect the custom board functions
- Verify recommendations as per the data sheet or
EVM implementation have been considered for the attached
device including terminations