SAM3N0A Atmel Corporation, SAM3N0A Datasheet - Page 341

• Manufacturer Part Number: SAM3N0A
• Manufacturer: Atmel Corporation

24. Power Management Controller (PMC)
24.1
24.2
11011A–ATARM–04-Oct-10
Description
Embedded Characteristics
The Power Management Controller (PMC) optimizes power consumption by controlling all sys-
tem and user peripheral clocks. The PMC enables/disables the clock inputs to many of the
peripherals and the Cortex-M3 Processor.
The Supply Controller selects between the 32 kHz RC oscillator or the crystal oscillator. The
unused oscillator is disabled automatically so that power consumption is optimized.
By default, at startup the chip runs out of the Master Clock using the fast RC oscillator running at
4 MHz.
The user can trim the 8 and 12 MHz RC Oscillator frequency by software.
The Power Management Controller provides the following clocks:
• MCK, the Master Clock, programmable from a few hundred Hz to the maximum operating
• Processor Clock (HCLK), must be switched off when entering the processor in Sleep Mode.
• Free running processor Clock (FCLK)
• the Cortex-M3 SysTick external clock
• Peripheral Clocks, typically MCK, provided to the embedded peripherals (USART, SPI, TWI,
• Programmable Clock Outputs can be selected from the clocks provided by the clock
frequency of the device. It is available to the modules running permanently, such as the
Enhanced Embedded Flash Controller.
TC, etc.) and are independently controllable. In order to reduce the number of clock names in
a product, the Peripheral Clocks are named MCK in the product datasheet.
generator and driven on the PCKx pins.
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