AT32UC3B0256-A2UR Atmel, AT32UC3B0256-A2UR Datasheet - Page 302

• Manufacturer Part Number: AT32UC3B0256-A2UR
• Description: MCU AVR32 256K FLASH 64-TQFP
• Manufacturer: Atmel
• Series: AVR®32 UC3r

Specifications of AT32UC3B0256-A2UR

• Package / Case: 64-TQFP, 64-VQFP
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Operating Temperature: -40°C ~ 85°C
• Speed: 60MHz
• Number Of I /o: 44
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Program Memory Size: 256KB (256K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Connectivity: I²C, IrDA, SPI, SSC, UART/USART, USB
• Core Size: 32-Bit
• Package: 64TQFP
• Device Core: AVR32
• Family Name: AT32
• Maximum Speed: 60 MHz
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 44
• Interface Type: I2S/SPI/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Figure 21-2. Baud Rate Generator
21.6.1.1
32059K–03/2011
CLK_USART/DIV
CLK
CLK_USART
Baud Rate in Asynchronous Mode
Reserved
USCLKS
The Baud Rate Generator is based upon a 16-bit divider, which is programmed with the CD field
of the Baud Rate Generator Register (BRGR). If CD is programmed at 0, the Baud Rate Gener-
ator does not generate any clock. If CD is programmed at 1, the divider is bypassed and
becomes inactive.
If the external CLK clock is selected, the duration of the low and high levels of the signal pro-
vided on the CLK pin must be longer than a CLK_USART period. The frequency of the signal
provided on CLK must be at least 4.5 times lower than CLK_USART.
If the USART is programmed to operate in asynchronous mode, the selected clock is first
divided by CD, which is field programmed in the Baud Rate Generator Register (BRGR). The
resulting clock is provided to the receiver as a sampling clock and then divided by 16 or 8,
depending on the programming of the OVER bit in MR.
If OVER is set to 1, the receiver sampling is 8 times higher than the baud rate clock. If OVER is
cleared, the sampling is performed at 16 times the baud rate clock.
The following formula performs the calculation of the Baud Rate.
This gives a maximum baud rate of CLK_USART divided by 8, assuming that CLK_USART is
the highest possible clock and that OVER is programmed at 1.
0
1
3
2
Baudrate
16-bit Counter
=
--------------------------------------------
(
CD
8 2 Over
SelectedClock
(
–
USCLKS= 3
)CD
0
SYNC
)
CD
>1
0
1
0
1
OVER
Sampling
Divider
FIDI
0
1
SYNC
AT32UC3B
CLK
BaudRate
Sampling
Clock
Clock
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