SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 39

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

8.1.3.10
8.1.4
8.2
8.2.1
8.2.2
11057A–ATARM–17-Feb-12
External Memories
Boot Strategies
External Memory Bus
Static Memory Controller
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 8-3.
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.
The 144-pin and 217-pin SAM3X features one External Memory Bus to offer interface to a wide
range of external memories and to any parallel peripheral.
• Integrates Four External Memory Controllers:
• Up to 24-bit Address Bus (up to 16 MBytes linear per chip select)
• Up to 8 chip selects, Configurable Assignment
• 8- or 16-bit Data Bus
• Multiple Access Modes supported
• Multiple device adaptability
GPNVMBit[#]
– Static Memory Controller
– NAND Flash Controller
– SLC NAND Flash ECC Controller
– Single Data Rate Synchronous Dynamic Random Access Memory (SDR-SDRAM)
– Byte Write or Byte Select Lines
– Asynchronous read in Page Mode supported (4- up to 32-byte page size)
0
1
2
General Purpose Non-volatile Memory Bits
Function
Security bit
Boot mode selection
Flash selection (Flash 0 or Flash 1)
SAM3X/A
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