Boot loader lock bits, Ee figure 94), Gure 94 – Rainbow Electronics ATmega162V User Manual
Page 218: Atmega162/v

218
ATmega162/V
2513E–AVR–09/03
Figure 94. Memory Sections
Note:
1. The parameters are given in Table 94 on page 228.
Boot Loader Lock Bits
If no Boot Loader capability is needed, the entire Flash is available for application code.
The Boot Loader has two separate sets of Boot Lock bits which can be set indepen-
dently. This gives the user a unique flexibility to select different levels of protection.
The user can select:
•
To protect the entire Flash from a software update by the MCU
•
To protect only the Boot Loader Flash section from a software update by the MCU
•
To protect only the Application Flash section from a software update by the MCU
•
Allow software update in the entire Flash
See Table 90 and Table 91 for further details. The Boot Lock bits can be set in software
and in Serial or Parallel Programming mode, but they can be cleared by a chip erase
command only. The general Write Lock (Lock bit mode 2) does not control the program-
0x0000
Flashend
Program Memory
BOOTSZ = '11'
Application Flash Section
Boot Loader Flash Section
Flashend
Program Memory
BOOTSZ = '10'
0x0000
Program Memory
BOOTSZ = '01'
Program Memory
BOOTSZ = '00'
Application Flash Section
Boot Loader Flash Section
0x0000
Flashend
Application Flash Section
Flashend
End RWW
Start NRWW
Application flash Section
Boot Loader Flash Section
Boot Loader Flash Section
End RWW
Start NRWW
End RWW
Start NRWW
0x0000
End RWW, End Application
Start NRWW, Start Boot Loader
Application Flash Section
Application Flash Section
Application Flash Section
Read-While-Wr
ite Section
No Read-While-Wr
ite Section
Read-While-Wr
ite Section
No Read-While-Wr
ite Section
Read While Wr
ite
Section
No
Read While Wr
ite
Section
Read-While-Wr
ite Section
No Read-While-Wr
ite Section
End Application
Start Boot Loader
End Application
Start Boot Loader
End Application
Start Boot Loader