CONFIG_SOC_ATMEL_SAM3_EXT_MAINCK

The main clock is being used to drive the PLL, and thus driving the processor clock.

Says y if you want to use external crystal oscillator to drive the main clock. Note that this adds about a second to boot time, as the crystal needs to stabilize after power-up.

The crystal used here can be from 3 to 20 MHz.

Says n here will use the internal fast RC oscillator running at 12 MHz.

Symbol:

SOC_ATMEL_SAM3_EXT_MAINCK
Type:

bool
Value:

“n”
User value:

(no user value)
Visibility:

“n”
Is choice item:

false
Is defined:

true
Is from env.:

false
Is special:

false
Prompts:
  • “Atmel SAM3 to use external crystal oscillator for main clock”
Default values:
  • n (value: “n”)
  • Condition: (none)
Selects:

(no selects)
Reverse (select-related) dependencies:
 

(no reverse dependencies)
Additional dependencies from enclosing menus and ifs:
 

SOC_ATMEL_SAM3 && ARM (value: “n”)
Locations:
  • ../arch/arm/soc/atmel_sam3/Kconfig:85