sam4s8c ATMEL Corporation, sam4s8c Datasheet - Page 40

• Manufacturer Part Number: sam4s8c
• Description: At91sam Arm-based Flash Mcu
• Manufacturer: ATMEL Corporation

10.6
40
Power Management Controller
Figure 10-2. Clock Generator Block Diagram
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.
The user can trim the 8 and 12 MHz RC Oscillator frequency by software.
• 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 Clock, UDPCK
• independent peripheral clocks, typically at the frequency of MCK
• three programmable clock outputs: PCK0, PCK1 and PCK2
XOUT32
XIN32
XOUT
XIN
Clock Generator
Management
32k RC OSC
12/8/4 MHz
12M Main
Slow Clock
Controller
Oscillator
PLL and
Divider A
Status
On Chip
Oscillator
On Chip
RC OSC
PLL and
Divider B
Power
Control
MAINSEL
XTALSEL
PLLA Clock
PLLACK
PLLB Clock
PLLBCK
Slow Clock
SLCK
Main Clock
MAINCK
11100AS–ATARM–27-Oct-11