Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD 数据表
产品代码
ATSAM4S-WPIR-RD
507
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
29.
Power Management Controller (PMC)
29.1
Description
The Power Management Controller (PMC) optimizes power consumption by controlling all system and user
peripheral clocks. The PMC enables/disables the clock inputs to many of the peripherals and the Cortex-M4
processor.
The Supply Controller selects between the 32 kHz RC oscillator or the slow crystal oscillator. The unused oscillator
The Supply Controller selects between the 32 kHz RC oscillator or the slow crystal oscillator. The unused oscillator
is disabled automatically so that power consumption is optimized.
By default, at start-up 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 frequencies by software.
By default, at start-up 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 frequencies by software.
29.2
Embedded Characteristics
The Power Management Controller provides the following clocks:
MCK, the Master Clock, programmable from a few hundred Hz to the maximum operating frequency of the
device. It is available to the modules running permanently, such as the Enhanced Embedded Flash
Controller.
Processor Clock (HCLK) , automatically switched off when entering the processor in Sleep Mode.
Free running processor Clock (FCLK)
The Cortex-M4 SysTick external clock
UDP Clock (UDPCK), required by USB Device Port operations.
Peripheral Clocks, typically MCK, provided to the embedded peripherals (USART, SPI, TWI, TC, etc.) and
independently controllable. In order to reduce the number of clock names in a product, the Peripheral Clocks
are named MCK in the product datasheet.
Programmable Clock Outputs can be selected from the clocks provided by the clock generator and driven on
the PCKx pins.
Write Protected Registers
The Power Management Controller also provides the following operations on clocks:
A main crystal oscillator clock failure detector.
A frequency counter on main clock and an on-the-fly adjustable main RC oscillator frequency.