Datasheet
105
SAM9263 [DATASHEET]
Atmel-6249N-ATARM-SAM9263-Datasheet_14-Mar-16
12.8 Hardware and Software Constraints
SAM-BA boot disposes of two blocks of internal SRAM. The first block is available for user code. Its size is
73728 bytes. The second block is used for variables and stacks.
The SD Card
(1)
, NAND Flash and DataFlash downloaded code size must be inferior to 72 K bytes.
The code is always downloaded from the DataFlash or NAND Flash device address 0x0000_0000 to the
address 0x0000_0000 of the internal SRAM (after remap).
The downloaded code must be position-independent or linked at address 0x0000_0000.
The DataFlash must be connected to NPCS0 of the SPI.
USB requirements:
Crystal or Input Frequencies supported by Software Auto-detection. See Table 12-1 on page 98 for
more informations.
Note: 1. Boot ROM does not support high capacity SDCards.
The MCI, the SPI and NAND Flash drivers use several PIOs in alternate functions to communicate with devices.
Care must be taken when these PIOs are used by the application. The devices connected could be unintentionally
driven at boot time, and electrical conflicts between peripherals output pins and the connected devices may
appear.
To assure correct functionality, it is recommended to plug in critical devices to other pins.
Table 12-7 contains a list of pins that are driven during the boot program execution. These pins are driven during
the boot sequence for a period of less than 1 second if no correct boot program is found.
For the DataFlash driven by the SPCK signal at 8 MHz, the time to download 72 Kbytes is reduced to 200 ms.
Before performing the jump to the application in internal SRAM, all the PIOs and peripherals used in the boot
program are set to their reset state.
Table 12-6. User Area Address
Start Address End Address Size (bytes)
0x3000000 0x312000 73728
Table 12-7. Pins Driven during Boot Program Execution
Peripheral Pin PIO Line
MCI1 MCCK PIOA6
MCI1 MCCDA PIOA7
MCI1 MCDA0 PIOA8
MCI1 MCDA1 PIOA9
MCI1 MCDA2 PIOA10
MCI1 MCDA3 PIOA11
SPI0 MOSI PIOA1
SPI0 MISO PIOA0
SPI0 SPCK PIOA2
SPI0 NPCS0 PIOA5
PIOD NANDCS PIOD15
DBGU DRXD PIOC30
DBGU DTXD PIOC31