C8051F581-IMR Silicon Labs, C8051F581-IMR Datasheet - Page 144

• Manufacturer Part Number: C8051F581-IMR
• Description: 8-bit Microcontrollers - MCU 50MIPS 128kB 8kB SPI
• Manufacturer: Silicon Labs

Specifications of C8051F581-IMR

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit

C8051F58x/F59x
SFR Definition 15.2. FLKEY: Flash Lock and Key
SFR Address = 0xB7; SFR Page = All Pages
144
Name
Reset
7:0 FLKEY[7:0] Flash Lock and Key Register.
Bit
Type
Bit
Name
7
0
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 regis-
ter. 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 perma-
nently 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 software.
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 disabled until the next reset.
6
0
5
0
Rev. 1.2
4
0
FLKEY[7:0]
R/W
Function
3
0
2
0
1
0
0
0