SPRAD21I May 2022 – September 2025 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP , AM62A1-Q1 , AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1 , AM62D-Q1 , AM62P , AM62P-Q1
The processor families support x16 boot mode input pins that can configured by custom board designers to boot from the required (designed) memory interface or peripheral.
For supported boot mode configurations, see the following FAQ:
Internal pulls (pullup or pulldown) are not enabled for the processor boot mode inputs during cold reset. The recommendation is to connect external pulls (10kΩ or 47kΩ) (pullup or pulldown) to configure the required boot mode. The recommendation is to not leave any of the boot mode inputs unconnected including reserved pins.
In use case where dip switches are used to configure the required boot modes, the recommendation is to use resistor divider value of 1kΩ (pullup) and 47kΩ (pulldown) for improved noise performance.
When the boot mode is configured using only resistors (without using dip switches), a standard resistor (same value can be used for pullup and pulldown) value can be used. As an example a 10kΩ or 47kΩ can be used since either pullup or pulldown is populated. The recommendation is to provide provision to connect pullup or pulldown to all boot mode pins including pins that are reserved or not used.
Currently BOOTMODE14 and BOOTMODE15 pins are Reserved for AM62x, AM62Ax and AM62D-Q1 processor families.
BOOTMODE14 and BOOTMODE15 pins are Reserved. Optionally, AM62P, AM62P-Q1 processor family can be configured for POST (Hardware Power-on-Self-Test) functionality when BOOTMODE15 = 1 and DS_DM_RESET_MASK = 0.
The recommendation is to add provision for pullup and pulldown for the boot mode inputs (pins) that have configuration capability for testing/debug (including provision for USB0 DFU, UART0 boot mode configuration), design flexibility, and future enhancement. The recommendation is to populate either pullup or pulldown for each boot mode pins. Connecting boot mode pins directly to ground or IO supply rail is not recommended or allowed since IOs have alternate function that can be configured after boot and can be unintentionally configured as output by the software.
Boot mode inputs (pins) are not fail-safe. The recommendation is to not apply any external inputs before the processor IO supply ramps. When connecting boot mode using pullups/pulldowns without the use of boot mode buffer the recommendation is to connect the IO supply that is connected to the IO supply for IO group referenced by the processor IOs. When using boot mode buffers the recommendation is to connect the IO supply that connects the processor IOs to the B-port supply pin of buffers (processor side). When external inputs from carrier board are connected to configure the boot mode inputs, the inputs are recommended to be driven after the processor supply ramps and are required to be stable before the MCU_PORz input is pulled high.
Based on the application requirement, a buffer that is driven only when reset status output (PORz_OUT or optionally RESETSTATz is low) can be used to drive the boot configuration inputs to the processor.
A series resistor (1kΩ) is recommended at the output of the buffer (to limit the output current in case the boot mode pins are configured as an output before the buffer OE is deasserted). For more information, see the processor-specific SK for implementation.