at91sam9260-cj ATMEL Corporation, at91sam9260-cj Datasheet - Page 252

• Manufacturer Part Number: at91sam9260-cj
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

Figure 25-2. Main Oscillator Block Diagram
25.4.1
Figure 25-3. Typical Crystal Connection
25.4.2
25.4.3
252
AT91SAM9260
Main Oscillator Connections
Main Oscillator Startup Time
Main Oscillator Control
The Clock Generator integrates a Main Oscillator that is designed for a 3 to 20 MHz fundamental
crystal. The typical crystal connection is illustrated in
required for crystals with frequencies lower than 8 MHz. For further details on the electrical char-
acteristics of the Main Oscillator, see the section “DC Characteristics” of the product datasheet.
The startup time of the Main Oscillator is given in the DC Characteristics section of the product
datasheet. The startup time depends on the crystal frequency and decreases when the fre-
quency rises.
To minimize the power required to start up the system, the main oscillator is disabled after reset
and slow clock is selected.
The software enables or disables the main oscillator so as to reduce power consumption by
clearing the MOSCEN bit in the Main Oscillator Register (CKGR_MOR).
Slow Clock
XOUT
SLCK
XIN
XIN
AT91 Microcontroller
Main Clock
OSCOUNT
Frequency
Oscillator
MOSCEN
Oscillator
XOUT
Counter
Counter
Main
Main
1K
GND
Main Clock
MAINCK
MAINRDY
MOSCS
MAINF
Figure
25-3. The 1 k
6221G–ATARM–31-Jan-08
Ω
resistor is only