36.5.3.4 Init
After each reset, the OTPC parses the User area to check its content. The header of
each packet will be read, depending on the header value some actions can be
triggered:
- If the header is corrupted, the init sequence is interrupted and the OTPC_ISR.COERR bit is set.
- If the INVLD field of the header is 3, the OTPC ignores the packet and jumps to the next header.
- If the LOCK bit of the header is set, the payload is read and the checksum computed during the read is compared to the checksum saved in the header. If the checksums do not match, the OTPC_ISR.CKERR bit will be set.
- If the PACKET field of the header is BOOT_CONFIGURATION, the address of the packet will be stored in the OTPC_BAR.BCADDR field. Any previous value stored in the OTPC_BAR.BCADDR field is lost.
- If the PACKET field of the header is SECURE_BOOT_CONFIGURATION, the address of the packet will be stored in the OTPC_BAR.SBCADDR field. Any previous value stored in the OTPC_BAR.SBCADDR field is lost.
- If the PACKET field of the header is HARDWARE_CONFIGURATION, the payload is read and stored in the OTPC User Hardware Configuration (OTPC_UHCxR) registers (unless the checksums do not match if the packet is locked, in that case the reset value of the OTPC_UHCxR registers is stored). Any previous value stored in the OTPC_UHCxR registers is lost.
- If the PACKET field of the header is CUSTOM, the address of the packet will be stored in the OTPC_CAR.CADDR field. Any previous value stored in the OTPC_CAR.CADDR field is lost.
At the end of the init sequence, the value of the last HARDWARE_CONFIGURATION “special“ packet found is applied to the hardware.