ATSAM3U_10 ATMEL [ATMEL Corporation], ATSAM3U_10 Datasheet - Page 40

• Manufacturer Part Number: ATSAM3U_10
• Description: AT91ARM Cortex M3-based Microcontrollers
• Manufacturer: ATMEL [ATMEL Corporation]

10.6
40
Power Management Controller
SAM3U Series
The Power Management Controller provides all the clock signals to the system. It provides:
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.
Figure 10-3.
The SysTick calibration value is fixed at 10500, which allows the generation of a time base of
1 ms with SystTick clock to 10.5 MHz (max HCLK/8).
• the Processor Clock HCLK
• the Free running processor clock FCLK
• the Cortex SysTick external clock
• the Master Clock MCK, in particular to the Matrix and the memory interfaces
• the USB Device HS Clock UDPCK
• independent peripheral clocks, typically at the frequency of MCK
• three programmable clock outputs: PCK0, PCK1 and PCK2
PLLBCK
MAINCK
PLLACK
SLCK
Power Management Controller Block Diagram
Master Clock Controller
MAINCK
PLLACK
PLLBCK
HSCK
SLCK
/1,/2,/4,...,/64
Prescaler
Programmable Clock Controller
USB Clock Controller
/1,/2,/4,...,/64
Prescaler
Sleep Mode
ON/OFF
Clock Controller
Processor
Controller
ON/OFF
Divider
Clock
Peripherals
ON/OFF
/8
HCK
int
SystTick
FCLK
MCK
periph_clk[..]
pck[..]
UDPCK
6430CS–ATARM–09-Apr-10