sam4s8c ATMEL Corporation, sam4s8c Datasheet - Page 41

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

10.7
10.8
10.9
11100AS–ATARM–27-Oct-11
Watchdog Timer
SysTick Timer
Real-Time Timer
Figure 10-3. Power Management Controller Block Diagram
The SysTick calibration value is fixed at 12500, which allows the generation of a time base of
1 ms with SysTick clock at 12.5 MHz (max HCLK/8 = 100 MHz/8 = 12500, so STCALIB =
0x30D4).
• 16-bit key-protected only-once Programmable Counter
• Windowed, prevents the processor to be in a deadlock on the watchdog access
• 24-bit down counter
• Self-reload capability
• Flexible System timer
• Real-Time Timer, allowing backup of time with different accuracies
– 32-bit Free-running backup Counter
– Integrates a 16-bit programmable prescaler running on slow clock
PLLACK
PLLBCK
MAINCK
SLCK
Master Clock Controller
MAINCK
PLLACK
PLLBCK
PLLBCK
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
MCK
HCK
int
SystTick
FCLK
periph_clk[..]
pck[..]
UDPCK
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