SAM9G20 Atmel Corporation, SAM9G20 Datasheet - Page 293

• 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

26.8
26.8.1
6384E–ATARM–05-Feb-10
Clock Switching Details
Master Clock Switching Timings
Table
from one selected clock to another one. This is in the event that the prescaler is de-activated.
When the prescaler is activated, an additional time of 64 clock cycles of the new selected clock
has to be added.
Table 26-1.
Notes:
Table 26-2.
To
Main Clock
SLCK
PLL Clock
To
PLLA Clock
PLLB Clock
26-1and
1. PLL designates either the PLL A or the PLL B Clock.
2. PLLCOUNT designates either PLLACOUNT or PLLBCOUNT.
From
From
Clock Switching Timings (Worst Case)
Clock Switching Timings (Worst Case)
Table 26-2
PLLCOUNT x SLCK +
0.5 x Main Clock +
0.5 x Main Clock +
2.5 x PLLx Clock
Main Clock
4 x SLCK +
4.5 x SLCK
give the worst case timings required for the Master Clock to switch
PLLACOUNT x SLCK
–
2.5 x PLLA Clock +
3 x PLLB Clock +
1.5 x PLLB Clock
PLLA Clock
4 x SLCK +
4 x SLCK +
PLLCOUNT x SLCK
2.5 x PLL Clock +
2.5 x Main Clock
4 x SLCK +
5 x SLCK +
SLCK
–
AT91SAM9G20
PLLBCOUNT x SLCK
2.5 x PLLB Clock +
3 x PLLA Clock +
1.5 x PLLA Clock
PLLB Clock
4 x SLCK +
4 x SLCK +
PLLCOUNT x SLCK
2.5 x PLL Clock +
3 x PLL Clock +
3 x PLL Clock +
1 x Main Clock
4 x SLCK +
4 x SLCK +
PLL Clock
5 x SLCK
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