SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 39

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

9.1.3.10
9.1.4
11057AS–ATARM–10-Feb-12
11057AS–ATARM–10-Feb-12
Boot Strategies
GPNVM Bits
The SAM-BA Boot is in ROM and is mapped in Flash at address 0x0 when GPNVM bit 1 is set
to 0.
The SAM3X/A series features three GPNVM bits that can be cleared or set respectively through
the “Clear GPNVM Bit” and “Set GPNVM Bit” commands of the EEFC0 User Interface.
Table 9-3.
The system always boots at address 0x0. To ensure maximum boot possibilities, the memory
layout can be changed via GPNVM.
A general-purpose NVM (GPNVM1) bit is used to boot either on the ROM (default) or from the
Flash.
The GPNVM bit can be cleared or set respectively through the "Clear General-purpose NVM Bit"
and "Set General-purpose NVM Bit" commands of the EEFC User Interface.
Setting GPNVM Bit 1 selects the boot from the Flash, clearing it selects the boot from the ROM.
Asserting ERASE clears GPNVM Bit 1 and thus selects the boot from the ROM by default.
GPNVM2 enables to select if Flash 0 or Flash 1 is used for the boot.
Setting GPNVM bit 2 selects the boot from Flash 1, clearing it selects the boot from Flash 0.
GPNVMBit[#]
0
1
2
General Purpose Non-volatile Memory Bits
Function
Security bit
Boot mode selection
Flash selection (Flash 0 or Flash 1)
SAM3X/A
SAM3X/A
41
41