17.5.2. Power Management
The MCLK will operate in all sleep modes if a synchronous clock is required in these modes.
Related Links
17.5.3. Clocks
The MCLK bus clock (CLK_MCLK_APB) can be enabled and disabled in the Main Clock module, and the
default state of CLK_MCLK_APB can be found in the Peripheral Clock Masking section. If this clock is
disabled, it can only be re-enabled by a reset.
The Generic Clock GCLK_MAIN is required to generate the Main Clocks. GCLK_MAIN is configured in
the Generic Clock Controller, and can be re-configured by the user if needed.
Related Links
GCLK - Generic Clock Controller
on page 121
on page 145
17.5.3.1. Main Clock
The main clock GCLK_MAIN is the common source for the synchronous clocks. This is fed into the
common 8-bit prescaler that is used to generate synchronous clocks to the CPU, AHBx, and APBx
modules.
17.5.3.2. CPU Clock
The CPU clock (CLK_CPU) is routed to the CPU. Halting the CPU clock inhibits the CPU from executing
instructions.
17.5.3.3. APBx and AHBx Clock
The APBx clocks (CLK_APBx) and the AHBx clocks (CLK_AHBx) are the root clock source used by
modules requiring a clock on the APBx and the AHBx bus. These clocks are always synchronous to the
CPU clock, but can be divided by a prescaler, and can run even when the CPU clock is turned off in sleep
mode. A clock gater is inserted after the common APB clock to gate any APBx clock of a module on
APBx bus, as well as the AHBx clock.
17.5.3.4. Clock Domains
The device has these synchronous clock domains:
•
High-Speed synchronous clock domain (HS Clock Domain). Frequency is f
hs
.
•
CPU synchronous clock domain (CPU Clock Domain). Frequency is f
CPU
.
•
Backup synchronous clock domain. (BUP Clock Domain). Frequency is f
BUP
.
See also the related links for the clock domain partitioning.
Related Links
on page 145
17.5.4. DMA
Not applicable.
17.5.5. Interrupts
The interrupt request line is connected to the Interrupt Controller. Using the MCLK interrupt requires the
Interrupt Controller to be configured first.
17.5.6. Events
Not applicable.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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