Datasheet

46
11057BS–ATARM–13-Jul-12
SAM3X/A
46
11057BS–ATARM–13-Jul-12
SAM3X/A
The Slow Clock generator is based on a 32 kHz crystal oscillator and an embedded 32 kHz RC
oscillator. The Slow Clock defaults to the RC oscillator, but the software can enable the crystal
oscillator and select it as the Slow Clock source.
The Supply Controller starts up the device by enabling the Voltage Regulator, then it generates
the proper reset signals to the core power supply.
It also enables to set the system in different low power modes and to wake it up from a wide
range of events.
10.5 Clock Generator
The Clock Generator is made up of:
• One Low Power 32,768 Hz Slow Clock Oscillator with bypass mode
• One Low Power RC Oscillator
• One 3 to 20 MHz Crystal or Ceramic-based Oscillator, which can be bypassed
• One factory-programmed Fast RC Oscillator; 3 output frequencies can be selected: 4, 8 or 12
MHz. By default, 4 MHz is selected. 8 MHz and 12 MHz output are factory-calibrated.
• One 480 MHz UPLL providing a clock for the USB OTG High Speed Controller. Input
frequency is 12 MHz (only).
• One 96 to 192 MHz programmable PLL (PLLA), capable to provide the clock MCK to the
processor and to the peripherals. The input frequency of the PLL A is between 8 and 16 MHz.