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 MCAN interface signals including polarity
- Mapping of processor pin (ball number) to the required functionality
(peripheral, signal name) on custom board (selected pin supports muxing
(multiplex) the IO for the required function) and naming of the signal as
per the processor data-sheet pin attributes signal name column (when using
standard peripherals).
- Matching of the polarity of the peripheral data interface signals between
the processor and the attached device (Example Mapping of TX->RX, Dout to
Din or similar connections)
- Verify the IO voltage level connected based on the buffer type implemented
for the IOs used to configure the interface
- Provision for series resistors added for all the MCAN interface signals and
placed near to the source for isolation or control of possible signal
reflections (data).
- Provision for parallel pull added for the processor or attached device
inputs that can float
- Connection of processor IO supply for IO group and attached device IO supply
(connected to the same supply source)
- Fail-safe operation of MCAN interface signals
- Addition of required bulk and high frequency capacitors, and value
Schematic Review
Follow the below list for the custom
schematic design:
- Series resistor value used
(0Ω) and the placement (near to source)
- Parallel pull value (10kΩ)
added for any of the processor or attached device IOs that can float (to
prevent the attached device inputs from floating until driven by the
host)
- Pullup referenced to (powered
by) the processor VDDSHVx for corresponding MCAN instance and pins
matches
- Supply rails connected to the
dual-voltage IO supply for IO group VDDSHVx referenced to (powered by) MCAN
peripherals and attached devices IO supply are connected to the same power
source and follow the ROC
- Provision for parallel pull
added for any of the processor or attached device IOs that can float
- MCAN interface signals are
not fail-safe. The recommendation is to apply the inputs only after the
processor supply ramps
Additional
- Processor IOs are not fail-safe.
No external input is recommended to be applied before the processor supply
ramps. The recommendation is to verify fail-safe operation when connected to
external interface signals. Applying an external input signal to the processor
MCAN inputs before processor supply ramps can cause voltage feed and can affect
the custom board functions.
- External ESD protection when the
interface signals are connected directly to external inputs