SAM7S16 Atmel Corporation, SAM7S16 Datasheet - Page 197

• Manufacturer Part Number: SAM7S16
• Manufacturer: Atmel Corporation

Specifications of SAM7S16

• Flash (kbytes): 16 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 55 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 21
• Ext Interrupts: 21
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

25.8
25.8.1
25.8.2
6175L–ATARM–28-Jul-11
Clock Switching Details
Master Clock Switching Timings
Clock Switching Waveforms
Table 25-1
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 25-1.
Figure 25-3. Switch Master Clock from Slow Clock to PLL Clock
To
Main Clock
SLCK
PLL Clock
Write PMC_MCKR
From
Master Clock
gives the worst case timings required for the Master Clock to switch from one
Slow Clock
PLL Clock
MCKRDY
Clock Switching Timings (Worst Case)
LOCK
PLLCOUNT x SLCK +
0.5 x Main Clock +
0.5 x Main Clock +
2.5 x PLLx Clock
Main Clock
4.5 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
–
SAM7S Series
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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