ATxmega256A3 Atmel Corporation, ATxmega256A3 Datasheet - Page 87

• 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
7.10.1
8077H–AVR–12/09
Register Description - Oscillator
CTRL - Oscillator Control Register
• Bit 0 - RTCEN: RTC Clock Source Enable
Setting the RTCEN bit enables the selected clock source for the Real Time Counter.
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 should be configured with the
desired multiplication factor and input source.
page
• Bit 3 - XOSCEN: External Oscillator Enable
Setting this bit enables the selected external clock source, refer to
Register” on page 88
external clock source should be allowed time to become stable before it is selected as source for
the System Clock.
• Bit 2 - RC32KEN: 32.768 kHz Internal RC Oscillator Enable
Setting this bit enables the 32.768 kHz internal RC oscillator. The oscillator must be stable
before it is selected as source for the System Clock.
on page 88.
• Bit 1- RC32MEN: 32 MHz Internal RC Oscillator Enable
Setting this bit will enable the 32 MHz internal RC oscillator. The oscillators should be allowed
time to become stable before wither is selected as source for the System Clock.
Oscillator Status Register” on page 88.
• Bit 0 - RC2MEN: 2 MHz Internal RC Oscillator enable
Setting this bit enables the 2MHz internal RC oscillator. The oscillator should be allowed time to
become stable before wither is selected as source for the System Clock.
lator Status Register” on page 88.
By default the 2 Mhz Internal RC Oscillator is enabled and this bit is set.
Bit
+0x00
Read/Write
Initial Value
• Bit 7:5 - Reserved
88..
R
7
0
-
See ”STATUS - Oscillator Status Register” on page 88.
for details on how to select and enable an external clock source. The
R
6
0
-
R
5
0
-
PLLEN
R/W
4
0
See ”STATUS - Oscillator Status Register” on
XOSCEN
R/W
3
0
See ”STATUS - Oscillator Status Register”
RC32KEN
R/W
2
0
”XOSCCTRL - XOSC Control
RC32MEN
R/W
1
0
See ”STATUS - Oscil-
XMEGA A
RC2MEN
R/W
See ”STATUS -
0
1
CTRL
87