AT32UC3A3128 Atmel Corporation, AT32UC3A3128 Datasheet - Page 511

• Manufacturer Part Number: AT32UC3A3128
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A3128

• Flash (kbytes): 128 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 32
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 110
• Ext Interrupts: 110
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• Ssc: 1
• Sd / Emmc: 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
• Dac Channels: 2
• Dac Resolution (bits): 16
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0 to 3.6
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 18
• Input Capture Channels: 12
• Pwm Channels: 12
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

24.7.1.1
24.7.1.2
32072G–11/2011
Clock divider
Transmitter clock management
Figure 24-4. Divided Clock Block Diagram
The peripheral clock divider is determined by the 12-bit Clock Divider field (its maximal value is
4095) in the Clock Mode Register (CMR.DIV), allowing a peripheral clock division by up to 8190.
The divided clock is provided to both the receiver and transmitter. When this field is written to
zero, the clock divider is not used and remains inactive.
When CMR.DIV is written to a value equal to or greater than one, the divided clock has a fre-
quency of CLK_SSC divided by two times CMR.DIV. Each level of the divided clock has a
duration of the peripheral clock multiplied by CMR.DIV. This ensures a 50% duty cycle for the
divided clock regardless of whether the CMR.DIV value is even or odd.
Figure 24-5.
Table 24-2.
The transmitter clock is generated from the receiver clock, the divider clock, or an external clock
scanned on the TX_CLOCK pin. The transmitter clock is selected by writing to the Transmit
Clock Selection field in the Transmit Clock Mode Register (TCMR.CKS). The transmit clock can
Maximum
CLK_SSC / 2
Divided Clock
Divided Clock
Range of Clock Divider
CLK_SSC
CLK_SSC
Divided Clock Generation
DIV = 3
DIV = 1
CLK_SSC
/ 2
Divided Clock Frequency = CLK_SSC/2
Divided Clock Frequency = CLK_SSC/6
Clock Divider
12-bit Counter
Minimum
CLK_SSC / 8190
CMR
Divided Clock
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