AT32UC3A0128AU Atmel Corporation, AT32UC3A0128AU Datasheet - Page 62

• Manufacturer Part Number: AT32UC3A0128AU
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A0128AU

• Flash (kbytes): 128 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 32
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 109
• Ext Interrupts: 109
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 1
• Uart: 4
• Ssc: 1
• Ethernet: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 16
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0-3.6 or (1.65-1.95+3.0-3.6)
• Operating Voltage (vcc): 3.0-3.6 or (1.65-1.95+3.0-3.6)
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 10
• Output Compare Channels: 16
• Input Capture Channels: 6
• Pwm Channels: 13
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

32058K AVR32-01/12
13.5.8.1
13.5.8.2
13.5.8.3
Enabling a generic clock
Disabling a generic clock
Changing clock frequency
Figure 13-5. Generic clock generation
A generic clock is enabled by writing the CEN bit in GCCTRL to 1. Each generic clock can use
either Oscillator 0 or 1 or PLL0 or 1 as source, as selected by the PLLSEL and OSCSEL bits.
The source clock can optionally be divided by writing DIVEN to 1 and the division factor to DIV,
resulting in the output frequency:
The generic clock can be disabled by writing CEN to 0 or entering a sleep mode that disables
the PB clocks. In either case, the generic clock will be switched off on the first falling edge after
the disabling event, to ensure that no glitches occur. If CEN is written to 0, the bit will still read as
1 until the next falling edge occurs, and the clock is actually switched off. When writing CEN to 0,
the other bits in GCCTRL should not be changed until CEN reads as 0, to avoid glitches on the
generic clock.
When the clock is disabled, both the prescaler and output are reset.
When changing generic clock frequency by writing GCCTRL, the clock should be switched off by
the procedure above, before being re-enabled with the new clock source or division setting. This
prevents glitches during the transition.
PLL0 clock
Osc0 clock
Osc1 clock
PLL1 clock
f
GCLK
= f
OSCSEL
SRC
PLLSEL
0
1
/
(2*(DIV+1))
Divider
DIV
DIVEN
0
1
Controller
Sleep
Mask
CEN
AT32UC3A
Generic Clock
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