8.2.2. atsam

Board support package for the Atmel SAM V71/V70/E70/S70 chip platform.

The BSP is customized to a particular board/chip variant by means of BSP config options.

Use ATSAM_CHIP = XYZ to select the chip variant where XYZ is one of same70j19, same70j20, same70j21, same70n19, same70n20, same70n21, same70q19, same70q20, same70q21, sams70j19, sams70j20, sams70j21, sams70n19, sams70n20, sams70n21, sams70q19, sams70q20, sams70q21, samv71j19, samv71j20, samv71j21, samv71n19, samv71n20, samv71n21, samv71q19, samv71q20, samv71q21. By default the BSP uses the ATSAMV71Q21 chip. Not all variants are tested.

Use ATSAM_SDRAM = XYZ to select the SDRAM variant where XYZ is one of is42s16100e-7bli, is42s16320f-7bl and mt48lc16m16a2p-6a. Not all variants are tested with all controller and speed combinations.

Use BOARD_MAINOSC = XYZ to set the main oscillator frequency in Hz (default 12MHz).

Use ATSAM_MCK = XYZ to set the MCK frequency that should be used. The default case (123000000) enables operation of an external SDRAM on the SAMv71 Explained evaluation kit. Some other configurations (e.g. 150MHz) would be too fast on that board.

Your application can also overwrite the clock settings. If you have a bootloader with one setting in your internal flash and an application with another setting in your external SDRAM, you should also use the ATSAM_CHANGE_CLOCK_FROM_SRAM = 1 option. To overwrite the clock settings, define the following structures in your application:

const struct atsam_clock_config atsam_clock_config = {
  .pllar_init = my_custom_pllar_value,
  .mckr_init = my_custom_mckr_value,
  .mck_freq = my_resulting_mck_frequency
};

const struct BOARD_Sdram_Config BOARD_Sdram_Config = {
  .sdramc_tr = my_custom_sdramc_tr_value,
  .sdramc_cr = my_custom_sdramc_cr_value,
  .sdramc_mdr = my_custom_sdramc_mdr_value,
  .sdramc_cfr1 = my_custom_sdramc_cfr1_value
};

Use ATSAM_SLOWCLOCK_USE_XTAL = 0 to disable the usage of the external 32 kHz oscillator for the slow clock. This is useful for example for the SAM E70 Xplained kit.

Use ATSAM_CONSOLE_BAUD = XYZ to set the initial baud for console devices (default 115200).

Use ATSAM_CONSOLE_DEVICE_TYPE = XYZ to set the device type for /dev/console, use 0 for USART and 1 for UART (default USART).

Use ATSAM_CONSOLE_DEVICE_INDEX = XYZ to set the device index for /dev/console (default 1, e.g. USART1).

Use ATSAM_CONSOLE_USE_INTERRUPTS = XYZ to set the use interrupt driven mode for console devices (used by default).

Use ATSAM_MEMORY_NULL_SIZE = XYZ to set the size of NULL pointer protection area in bytes (default 0x00000000).

Use ATSAM_MEMORY_TCM_SIZE = XYZ to set the size of tightly coupled memories (TCM) in bytes (default 0x00000000). Note: ITCM is reduced by the ATSAM_MEMORY_NULL_SIZE.

Use ATSAM_MEMORY_QSPIFLASH_SIZE = XYZ to set the size of QSPI flash in bytes (default 0x00200000).

The pins may be configured by the application at link-time. See <bsp/pin-config.h>.

The clock driver uses the ARMv7-M Systick.

The console driver supports the USART and UART devices.

The default linker command file places the code into the internal flash. There are the alternative linker command files linkcmds.sdram, linkcmds.qspiflash and linkcmds.intsram that use other memories. To use them in your application, add the following linker flags: LDFLAGS += -qnolinkcmds -T linkcmds.XYZ.

The fast text section uses the ITCM. The fast data section uses the DTCM.

Data and instruction cache are enabled during system start. The RTEMS cache manager is supported with exception of the freeze functions.