Overview of memory contents:
- eFuse
- Contains mostly critical chip-trim items needed before bootloader starts
- Interfaced through the FLASH module in the digital core
- FLASH trim
- Ram repair
- Analog trim (band gap, brownout, selected regulators, internal 48-MHz RC Oscillator)
- JTAG TAP/DAP lock
- CRC check (8 bits)
- The only critical item here is the JTAG TAP/DAP lock that is locked by default (if a fuse is blown).
- FCFG:
- Currently a separate FLASH block
- All trims plus entire device configuration
- FLASH trim to support erase/write
- Module trim (analog, RF+++)
- Chip configuration (ID, device type, package size, pinout++, production test data)
- Bootloader configuration
- Security
- TI FA Analysis option
- JTAG TAP/DAP lock override
- Bootloader enable
- Customer configuration (last page in FLASH):
- Bootloader disable
- JTAG DAP/TAP disable
- TI FA analysis disable
- Customer configuration area write or erase protection
- Other configuration not related to security
Configuration memory:
- RO
- OTP, 1 kB read interface (write through FMC)
- RO
- ENGR 1 kB read interface (write through FMC)
- CCFG
- FLASH sector 4 kB read interface (write through FMC)
- RO
- EFUSE, only accessible through MMR interface
The ROM is preprogrammed with a serial bootloader (SPI or UART). For applications that require in-field programmability, the royalty-free bootloader acts as an application loader and supports in-field firmware updates. The bootloader either executes automatically if no valid image has been written to the FLASH, or the bootloader may be started through a configurable GPIO backdoor. The bootloader may not be called from application code.