SPRADO2 November 2024 AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1
Boot mode inputs do not have internal pullup or pulldown resistors that are active during processor power-up or reset. The recommendation is to connect external pullups or pulldowns to set the required boot mode.
When dip switches are used, use a resistor divider ratio of 470Ω (pullup) and 47kΩ (pulldown) for improved noise performance.
When the boot mode is configured using only resistors, a standard resistor (same value for pullup or pulldown) value. An example is a 10kΩ or similar is recommended because either the pullup or pulldown are used.
The recommendation is to connect pullup or pulldowns to boot mode pins marked as Reserved or not used.
BOOTMODE 14 and BOOTMODE 15 pins are Reserved for AM62Ax processor family.
Add provision for pullup and pulldown for all the boot mode pins that have configuration capability for debugging, design flexibility, and future enhancement. Populate either pullup or pulldown for each boot mode pins. Direct connection of boot mode pins to ground or IO supply rail is not recommended or allowed since IOs have alternate configuration and, intentionally or unintentionally, are configured as output by the software.
Consider that the boot mode input pins are not fail-safe when boot mode configurations are driven from an external input or a base board.
Based on the application requirement, a buffer that is driven only when reset (MCU_PORz) is asserted (low) is used to present the boot configuration to the processor.
If the boot mode pins are configured as an output during normal operation, a series resistor (approximately 1kΩ) is recommended at the output of the buffers. For more information, see the processor-specific SK for implementation.