ATxmega256A3U Atmel Corporation, ATxmega256A3U Datasheet - Page 94

• Manufacturer Part Number: ATxmega256A3U
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3U

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 50
• Ext Interrupts: 50
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 10
• Twi (i2c): 2
• Uart: 7
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 16
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 7
• Output Compare Channels: 22
• Input Capture Channels: 22
• Pwm Channels: 22
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

7.10
7.10.1
8331A–AVR–07/11
Register Description — Oscillator
CTRL – Oscillator Control Register
These bits are unused and reserved for future use. For compatibility with future devices, always
write these bits to zero when this register is written.
• Bit 4 – PLLEN: PLL Enable
Setting this bit enables the PLL. Before the PLL is enabled, it must be configured with the
desired multiplication factor and clock source.
page
• Bit 3 – XOSCEN: External Oscillator Enable
Setting this bit enables the selected external clock source. Refer to
trol Register” on page 95
clock source should be allowed time to stabilize before it is selected as the source for the system
clock.
• Bit 2 – RC32KEN: 32.768kHz Internal Oscillator Enable
Setting this bit enables the 32.768kHz internal oscillator. The oscillator must be stable before it
is selected as the source for the system clock.
page 95.
• Bit 1 – RC32MEN: 32MHz Internal Oscillator Enable
Setting this bit will enable the 32MHz internal oscillator. The oscillator must be stable before it is
selected as the source for the system clock.
95.
• Bit 0 – RC2MEN: 2MHz Internal Oscillator Enable
Setting this bit enables the 2MHz internal oscillator. The oscillator must be stable before it is
selected as the source for the system clock.
95.
By default, the 2MHz internal oscillator is enabled and this bit is set.
Bit
+0x00
Read/Write
Initial Value
• Bit 7:5 – Reserved
95..
See ”STATUS – Oscillator Status Register” on page 95.
R
7
–
0
R
6
–
0
for details on how to select the external clock source. The external
R
5
–
0
PLLEN
R/W
4
0
See ”STATUS – Oscillator Status Register” on page
See ”STATUS – Oscillator Status Register” on page
See ”STATUS – Oscillator Status Register” on
See ”STATUS – Oscillator Status Register” on
XOSCEN
R/W
Atmel AVR XMEGA AU
3
0
RC32KEN
R/W
2
0
”XOSCCTRL – XOSC Con-
RC32MEN
R/W
1
0
RC2MEN
R/W
0
1
CTRL
94