Datasheet

SAM9G20

DS60001516A-page 74  2017 Microchip Technology Inc.

Figure 12-7: Serial DataFlash Download

12.7 NAND Flash Boot

The NAND Flash Boot program searches for a valid application in the NAND Flash memory. The first block must be guaranteed by the

manufacturer. There is no ECC check.

If a valid application is found, this application is loaded into internal SRAM and executed by branching at address 0x0000_0000 after

remap. See “Valid Image Detection” for more information on Valid Image Detection.

12.7.1 Supported NAND Flash Devices

Any 8- or 16-bit NAND Flash Device.

End

Read the first 8 instructions (32 bytes).

Decode the sixth Arm vector

Yes

Read the DataFlash into the internal SRAM.

(code size to read in vector 6)

Restore the reset value for the peripherals.

Set the PC to 0 and perform the REMAP

to jump to the downloaded application

Send status command

8 vectors

(except vector 6) are LDR

or Branch instruction

Yes

Start

Is status OK ?

Jump to next boot

solution