Datasheet

41
11057BS–ATARM–13-Jul-12
SAM3X/A
41
11057BS–ATARM–13-Jul-12
SAM3X/A
The SAM-BA Boot is in ROM and is mapped in Flash at address 0x0 when GPNVM bit 1 is set
to 0.
9.1.3.10 GPNVM Bits
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.
9.1.4 Boot Strategies
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.
Table 9-3. General Purpose Non-volatile Memory Bits
GPNVMBit[#] Function
0 Security bit
1 Boot mode selection
2 Flash selection (Flash 0 or Flash 1)