Atmel Evaluation Kit AT91SAM9G25-EK AT91SAM9G25-EK Data Sheet

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SAM9G25 [DATASHEET]

11032C–ATARM–25-Jan-13

The NVM bootloader program first initializes the PIOs related to the NVM device. Then it configures the right peripheral 
depending on the NVM and tries to access this memory. If the initialization fails, it restores the reset values for the PIO 
and the peripheral and then tries the same operations on the next NVM of the sequence.

If the initialization is successful, the NVM bootloader program reads the beginning of the NVM and determines if the NVM 
contains valid code.

If the NVM does not contain valid code, the NVM bootloader program restores the reset value for the peripherals and 
then tries the same operations on the next NVM of the sequence.

If valid code is found, this code is loaded from NVM into internal SRAM and executed by branching at address 
0x0000_0000 after remap. This code may be the application code or a second-level bootloader. All the calls to functions 
are PC relative and do not use absolute addresses.

End

Valid code detection in NVM

Yes

Copy the valid code 

from external NVM to internal SRAM.

Restore the reset values for the peripherals.

Perform the REMAP and set the PC to 0  

to jump to the downloaded application

Initialize NVM

NVM contains valid code

Yes

Start

Initialization OK ?

Restore the reset values

for the peripherals and 

Jump to next boot solution

No

No