Datasheet

24
6062LS–ATARM–23-Mar-09
AT91SAM9261
9.2 Reset Controller
• Based on two Power-on-Reset cells
• Status of the last reset
– Either cold reset, first reset, soft reset, user reset, watchdog reset, wake-up reset
• Controls the internal resets and the NRST pin output
9.3 Shutdown Controller
• Shutdown and Wake-up logic:
– Software programmable assertion of the SHDN pin
– Deassertion Programmable on a WKUP pin level change or on alarm
9.4 General-purpose Backup Registers
• Four 32-bit general-purpose backup registers
9.5 Clock Generator
• Embeds the Low-power 32768 Hz Slow Clock Oscillator
– Provides the permanent Slow Clock to the system
• Embeds the Main Oscillator
– Oscillator bypass feature
– Supports 3 to 20 MHz crystals
• Embeds Two PLLs
– Outputs 80 to 240 MHz clocks
– Integrates an input divider to increase output accuracy
– 1 MHz minimum input frequency
• Provides SLCK, MAINCK, PLLACK and PLLBCK.
Figure 9-2. Clock Generator Block Diagram
Power
Management
Controller
XIN
XOUT
PLLRCA
Slow Clock
SLCK
Main Clock
MAINCK
PLLA Clock
PLLACK
ControlStatus
PLL and
Divider B
PLLRCB
PLLB Clock
PLLBCK
XIN32
XOUT32
Slow Clock
Oscillator
Main
Oscillator
PLL and
Divider A
Clock Generator