CPU Clock Domain
Peripheral Clock
Default State
CLK_SERCOM1_APB
Enabled
CLK_SERCOM2_APB
Enabled
CLK_SERCOM3_APB
Enabled
CLK_SERCOM4_APB
Enabled
CLK_SERCOM5_APB
Enabled
CLK_SLCD_APB
Enabled
CLK_TC0_APB
Enabled
CLK_TC1_APB
Enabled
CLK_TC2_APB
Enabled
CLK_TC3_APB
Enabled
CLK_TCC0_APB
Enabled
CLK_TRNG_APB
Enabled
CLK_USB_AHB
Enabled
CLK_USB_APB
Enabled
CLK_WDT_APB
Enabled
Backup Clock Domain
Peripheral Clock
Default State
CLK_OSC32KCTRL_APB
Enabled
CLK_PM_APB
Enabled
CLK_SUPC_APB
Enabled
CLK_RSTC_APB
Enabled
CLK_RTC_APB
Enabled
When the APB clock is not provided to a module, its registers cannot be read or written. The module can
be re-enabled later by writing the corresponding mask bit to '1'.
A module may be connected to several clock domains (for instance, AHB and APB), in which case it will
have several mask bits.
Note that clocks should only be switched off if it is certain that the module will not be used: Switching off
the clock for the NVM Controller (NVMCTRL) will cause a problem if the CPU needs to read from the
Flash Memory. Switching off the clock to the MCLK module (which contains the mask registers) or the
corresponding APBx bridge, will make it impossible to write the mask registers again. In this case, they
can only be re-enabled by a system reset.
17.6.3. DMA Operation
Not applicable.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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