4.4.2 FLKEY: Flash Lock and Key
Bit
7
6
5
4
3
2
1
0
Name
FLKEY
Access
RW
Reset
0x00
SFR Page = ALL; SFR Address: 0xB7
Bit
Name
Reset
Access Description
7:0
FLKEY
0x00
RW
Flash Lock and Key.
Write:
This register provides a lock and key function for flash erasures and writes. Flash writes and erases are enabled by writing
0xA5 followed by 0xF1 to the FLKEY register. Flash writes and erases are automatically disabled after the next write or
erase is complete. If any writes to FLKEY are performed incorrectly, or if a flash write or erase operation is attempted while
these operations are disabled, the flash will be permanently locked from writes or erasures until the next device reset. If an
application never writes to flash, it can intentionally lock the flash by writing a non-0xA5 value to FLKEY from firmware.
Read:
When read, bits 1-0 indicate the current flash lock state.
00: Flash is write/erase locked.
01: The first key code has been written (0xA5).
10: Flash is unlocked (writes/erases allowed).
11: Flash writes/erases are disabled until the next reset.
EFM8UB3 Reference Manual
Flash Memory
silabs.com
| Building a more connected world.
Rev. 0.2 | 44