AT32UC3B1256-AUR Atmel, AT32UC3B1256-AUR Datasheet - Page 266

• Manufacturer Part Number: AT32UC3B1256-AUR
• Description: MCU AVR32 256K FLASH 48-TQFP
• Manufacturer: Atmel
• Series: AVR®32 UC3r

Specifications of AT32UC3B1256-AUR

• Package / Case: 48-TQFP, 48-VQFP
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Operating Temperature: -40°C ~ 85°C
• Speed: 60MHz
• Number Of I /o: 28
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Program Memory Size: 256KB (256K x 8)
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Connectivity: I²C, IrDA, SPI, SSC, UART/USART, USB
• Core Size: 32-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

20.7.1.1
20.7.1.2
32059J–12/2010
Clock divider
Transmitter clock management
Figure 20-4. 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 20-5.
Table 20-2.
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
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
AT32UC3B
266