Verify the following attributes for the processor
pins used in the custom board design:
- Processor pin number labeling
and naming (pin number associated with the processor symbol section)
corresponds to the correct pin numbers listed in the Pin Attributes
section of the processor-specific data sheet. The recommendation is to
maintain the processor-specific data sheet names internal to the symbol and
change the function (net) names as per the application use case.
- Supply voltages that are
connected to the processor power pins follow the Recommended Operating
Conditions.
- All processor pins (grouped
into functions and having separate symbol block) including reserved pins are
included in the schematics to minimize tool related and functional
errors.
- A number of processor IOs
TX (Output) and RX (Input) buffers are disabled and internal pulls (pullup
and pulldown) are turned off during reset and after reset. External pulls
(10kΩ or 47kΩ) are recommended to hold any attached device in a valid state
until software initializes the IOs trace is connected and IOs are not being
actively driven. When a TP is connected to the processor IO, a parallel pull
(47kΩ) is recommended. When adding pull is not feasible, the recommendation
is to route the traces away from high frequency signals.
- For improved custom board
performance, consider provisioning for external measurement of processor
supply rails (voltage), current draw for the supply rails and on-board
temperature measurement at hot spots.
For queries related to
processor-specific data sheet pin attributes, see the following FAQ:
[FAQ] AM625 / AM623 / AM620-Q1 / AM62L / AM62A /
AM62P / AM62D-Q1 / AM64x / AM243x Design Recommendations / Custom board hardware
design - Queries related to SOC data sheet Pin Attributes Excel
format