at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 25

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

9.6
9.7
9.8
9.9
9.10
6384B–ATARM–15-Dec-08
Periodic Interval Timer
Watchdog Timer
Real-time Timer
General-purpose Back-up Registers
Advanced Interrupt Controller
Figure 9-3.
• Includes a 20-bit Periodic Counter, with less than 1 µs accuracy
• Includes a 12-bit Interval Overlay Counter
• Real Time OS or Linux
• 16-bit key-protected only-once-Programmable Counter
• Windowed, prevents the processor being in a dead-lock on the watchdog access
• Real-time Timer 32-bit free-running back-up Counter
• Integrates a 16-bit programmable prescaler running on slow clock
• Alarm Register capable of generating a wake-up of the system through the Shutdown
• Four 32-bit backup general-purpose registers
• Controls the interrupt lines (nIRQ and nFIQ) of the ARM Processor
• Thirty-two individually maskable and vectored interrupt sources
Controller
PLLBCK
MAINCK
PLLACK
SLCK
AT91SAM9G20 Power Management Controller Block Diagram
Master Clock Controller
/1,/2,/4,.../64
®
Prescaler
/Windows CE
MAINCK
PLLACK
PLLBCK
PLLBCK
SLCK
Programmable Clock Controller
®
/1,/2,/4,/6
Divider
compliant tick generator
Divider
USB Clock Controller
AT91SAM9G20 Preliminary
/1,/2
Divider
/1,/2,/4
/1,/2,/4,...,/64
Prescaler
Clock Controller
Processor
Controller
ON/OFF
Idle Mode
ON/OFF
Clock
Peripherals
ON/OFF
PCK
int
MCK
periph_clk[..]
pck[..]
UDPCK
25