ATxmega256A3 Atmel Corporation, ATxmega256A3 Datasheet - Page 89

• Manufacturer Part Number: ATxmega256A3
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3

• 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 Speed: No
• Usb Interface: No
• 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

7.10.4
8077H–AVR–12/09
XOSCFAIL - XOSC Failure Detection Register
Table 7-5.
• Bit 5 - X32KLPM: Crystal Oscillator 32.768 kHz Low Power Mode
Setting this bit enables low power mode for the 32.768 kHz Crystal Oscillator. This will reduce
the swing on the TOSC2 pin.
• Bit 4 - Reserved
This bit is reserved and will always be read as zero. For compatibility with future devices, always
write this bit to zero when this register is written.
• Bit 3:0 - XOSCSEL[3:0]: Crystal Oscillator Selection
These bits select the type and start-up time for the crystal or resonator that is connected to the
XTAL or TOSC pins. See
selected as source for System Clock, see
configuration can not be changed.
Table 7-6.
Notes:
Bit
+0x03
Read/Write
Initial Value
FRQRANGE[1:0]
XOSCSEL[3:0]
0000
0010
0011
0111
1011
1. This option should only be used when frequency stability at start-up is not important for the
2. This option is intended for use with ceramic resonators and will ensure frequency stability at
00
01
10
11
application. The option is not suitable for crystals.
start-up. It can also be used when the frequency stability at start-up is not important for the
application.
7
–
R
0
Oscillator frequency range selection
External Oscillator selection and Startup Time
Group Configuration
R
6
–
0
Group Configuration
Table 7-6
XTAL_256CLK
XTAL_1KCLK
XTAL_16KCLK
12TO16
04TO2
9TO12
2TO9
EXTCLK
32KHZ
R
5
–
0
for crystal selections. If external clock or external oscillator is
(2)
(1)
R
4
–
0
”CTRL - Oscillator Control Register” on page
Frequency range
12 MHz - 16 MHz
0.4 MHz - 2 MHz
9 MHz - 12 MHz
2 MHz - 9 MHz
R
Selected Clock Source
3
–
0
0.4 - 16 MHz XTAL
0.4 - 16 MHz XTAL
0.4 - 16 MHz XTAL
32.768 kHz TOSC
External Clock
R
2
–
0
Recommended range
for capacitors C1 and C2 (pF)
XOSCFDIF
R/W
1
0
XMEGA A
XOSCFDEN
100
15
15
10
R/W
Start-up time
0
0
16K CLK
16K CLK
256 CLK
1K CLK
6 CLK
XOSCFAIL
87, this
89