AT91SAM9G10 datasheet(18/39 Pages) ATMEL

18 / 39 page

6462AS–ATARM–03-Jun-09

AT91SAM9G10

8.1.2.1

BMS = 1, Boot on Embedded ROM

The system boots using the Boot Program.

• Enable the 32,768 Hz oscillator

• Auto baudrate detection

• Downloads and runs an application from external storage media into internal SRAM

• Automatic detection of valid application

• Bootloader on a non-volatile memory

– SPI Serial Flash or DataFlash® connected on NPCS0 of the SPI0

–NAND Flash

– SDCard (boot ROM does not support high-capacity SDCards)

• SAM-BA Boot in case no valid program is detected in external NVM, supporting

– Serial communication on a DBGU

– USB Device HS Port

8.1.2.2

BMS = 0, Boot on External Memory

• Boot on slow clock (32,768 Hz)

• Boot with the default configuration for the Static Memory Controller, byte select mode, 16-bit

data bus, Read/Write controlled by Chip Select, allows boot on 16-bit non-volatile memory.

The customer-programmed software must perform a complete configuration.

To speed up the boot sequence when booting at 32 kHz EBI CS0 (BMS=0), the user must take

the following steps:

Program the PMC (main oscillator enable or bypass mode).

Program and start the PLL.

Reprogram the SMC setup, cycle, hold, mode timings registers for CS0 to adapt them

to the new clock

Switch the main clock to the new value.

8.2

External Memories

The external memories are accessed through the External Bus Interface (Bus Matrix Slave 3).

Refer to the memory map in Figure 8-1 on page 15.

AT91SAM9G10 датащи(PDF) 18 Page - ATMEL Corporation