ATAVRDISPLAYX Atmel, ATAVRDISPLAYX Datasheet - Page 79

• Manufacturer Part Number: ATAVRDISPLAYX
• Description: KIT EVAL XMEGA DISPLAY
• Manufacturer: Atmel

Specifications of ATAVRDISPLAYX

• Main Purpose: *
• Embedded: *
• Utilized Ic / Part: *
• Primary Attributes: *
• Secondary Attributes: *
• Silicon Manufacturer: Atmel
• Silicon Family Name: ATxmega
• Kit Contents: Board
• Features: Temperature Sensor, Mono Speaker Via Audio Amplifier
• Svhc: No SVHC (15-Dec-2010)
• Core Architecture: AVR
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.4.1.4
7.4.2
7.4.2.1
7.4.2.2
7.4.2.3
8077H–AVR–12/09
External Clock Sources
2 MHz Run-time Calibrated Internal Oscillator
0.4 - 16 MHz Crystal Oscillator
External Clock Input
32.768 kHz Crystal Oscillator
This RC oscillator provides an approximate 2 MHz clock. The oscillator employs a Digital Fre-
quency Looked Loop (DFLL) that can be enabled for automatic run-time calibration of the
oscillator. A factory-calibrated value is written to the 2 MHz DFLL Calibration Register during
reset to ensure that the oscillator is running within its specification. The calibration register can
also be written from software for manual run-time calibration of the oscillator.
The XTAL1 and XTAL2 pins can be used to drive an external oscillator, either a quartz crystal or
a ceramic resonator. XTAL1 can be used as input for an external clock signal. The TOSC1 and
TOSC2 pins is dedicated for driving a 32.768 kHz crystal oscillator.
This oscillator can operate in four different modes, optimized for different frequency ranges, all
within 0.4 - 16 MHz.
Figure 7-2.
Two capacitors, C1 and C2, may be added to match the required load capacitance for the con-
nected crystal.
To drive the device from an external clock source, XTAL1 must be driven as shown in
3 on page
Figure 7-3.
A 32.768 kHz crystal oscillator can be connected between TOSC1 and TOSC2 by enabling a
dedicated Low Frequency Oscillator input circuit. A typical connection is shown in Figure
79. In this mode, XTAL2 can be used as a general I/O pin.
Crystal Oscillator Connection
External Clock Drive Configuration
Figure 7-2
P u r p o s e
E x t e r n a l
G e n e r a l
S i g n a l
C l o c k
shows a typical connection of a crystal oscillator or resonator.
I / O
C 2
C 1
X T A L 2
X T A L 1
X T A L 2
X T A L 1
G N D
XMEGA A
Figure 7-
Figure
79