7.4.8.3 Write Decryption Keys, or Control Bits, in the Fuse Boxes

CommandDescription
0x00000000_DE05_5345ACBAAfter Reset, unblock the bootloader
0x00000000_DE05_ACBA5345
0x00000000_0007_XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXWrite the decryption key KEY_ENC in the Buffer register
0x00000000_0008_00000000Write the Buffer register to the Tamper register for KEY_ENC_FUSES
0x00000000_000C_00000000Blow fuses at corresponding fuse box
0x00000000_0012_00000000Check bootloader status to see if the process of blowing fuses has finished. Answers:
  • 0x”Bootloader Hardware signature”_0000_ 00000001 (fuse blowing active)
  • 0x”Bootloader Hardware signature”_0000_ 00000000 (bootloader ready)
0x00000000_0007_XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXWrite the signature/authentication key KEY_TAG in the Buffer register
0x00000000_0009_00000000Write the Buffer register to the Tamper register for KEY_TAG_FUSES
0x00000000_000C_00000000Blow fuses at corresponding fuse box
0x00000000_0012_00000000Check bootloader status to see if the process of blowing fuses has finished. Answers:
  • 0x”Bootloader Hardware signature”_0000_ 00000001 (fuse blowing active)
  • 0x”Bootloader Hardware signature”_0000_ 00000000 (bootloader ready)
0x00000000_0007_XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXWrite the signature/authentication key KEY_TAG in the Buffer register
0x00000000_000B_00000000Write the Buffer register to the Tamper register for CONTROL_FUSES
0x00000000_000C_00000000Blow fuses at corresponding fuse box
0x00000000_0012_00000000Check bootloader status to see if the process of blowing fuses has finished. Answers:
  • 0x”Bootloader Hardware signature”_0000_ 00000001 (fuse blowing active)
  • 0x”Bootloader Hardware signature”_0000_ 00000000 (bootloader ready)
0x00000000_0010_00000000Read CONTROL_FUSES fuse value to its Tamper register to load the new value in the system