SAM9G20 Atmel Corporation, SAM9G20 Datasheet - Page 178

• Manufacturer Part Number: SAM9G20
• Manufacturer: Atmel Corporation

Specifications of SAM9G20

• Flash (kbytes): 0 Kbytes
• Pin Count: 217
• Max. Operating Frequency: 400 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 96
• Ext Interrupts: 96
• Usb Transceiver: 3
• Usb Speed: Full Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 1
• Uart: 7
• Ssc: 1
• Ethernet: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: Yes
• Adc Channels: 4
• Adc Resolution (bits): 10
• Adc Speed (ksps): 95
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 0.9 to 1.1
• Fpu: No
• Mpu / Mmu: No/Yes
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

21.5
21.6
178
Main Clock
Main Clock Selection
SAM9G35
Figure 21-3. Main Clock Block Diagram
The Main Clock has two sources:
The main clock can be generated either by an external 12 MHz crystal oscillator or by the on-
chip 12 MHz RC oscillator. This fast RC oscillator allows the processor to start or restart in a few
microseconds when 12 MHz internal RC is selected.
The 12 MHz crystal oscillator can be bypassed by setting the bit MOSCXTBY to accept an exter-
nal main clock on XIN.
• 12 MHz Fast RC Oscillator which starts very quickly and is used at startup
• 3 to 20 MHz Crystal Oscillator, which can be bypassed
Slow Clock
XOUT
SLCK
XIN
MOSCRCEN
MOSCRCEN
3-20 MHz Crystal
MOSCXTCNT
Main Clock
MOSCXTEN
MOSCXTEN
Frequency
3-20 MHz
Oscillator
Oscillator
Oscillator
Fast RC
12 MHz
Counter
Crystal
Counter
MOSCRCF
MOSCSEL
MAINRDY
MOSCRCS
MOSCXTS
MOSCSEL
MAINF
1
0
Main Clock
11053B–ATARM–22-Sep-11
MOSCSELS
MAINCK