The following apply to all or multiple
boot modes that are OSPI-related.
Note: When using a OSPI\SPI flash device
greater than 128 Mb, a flash device package with a RESET signal must be used. The
reason is that the ROM only uses 3 byte addressing mode (address is 24-bits). To
address the full memory address range, software typically switches to 4-byte
addressing mode. If a reset to the processor occurs (for example, due to a warm
reset), the ROM executes expecting 3-byte addressing mode, but the flash will have
been left in 4-byte addressing mode. For the flash device to return to 3-byte
addressing mode, it must be reset using this signal. This typically can be achieved
by using the RESET signal on the flash memory device. ROM code does not issue a
software reset command.
Refer to the AM263Px OSPI,QSPI Flash Selection
Guide for additional details.