ATSAM3U4CA-CU Atmel, ATSAM3U4CA-CU Datasheet - Page 456

• Manufacturer Part Number: ATSAM3U4CA-CU
• Description: IC MCU 32BIT 256KB FLSH 100TFBGA
• Manufacturer: Atmel
• Series: SAM3Ur

Specifications of ATSAM3U4CA-CU

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 96MHz
• Connectivity: EBI/EMI, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
• Number Of I /o: 57
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 52K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 4x10b, 4x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TFBGA
• Processor Series: ATSAM3x
• Core: ARM Cortex M3
• Data Bus Width: 32 bit
• Data Ram Size: 52 KB
• Interface Type: 3xUSART, TWI, 4xSPI, Bus
• Maximum Clock Frequency: 96 MHz
• Number Of Programmable I/os: 57
• Number Of Timers: 8
• Operating Supply Voltage: 1.62 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-CM3, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: ATSAM3U-EK
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

27.4
27.4.1
456
Main Clock
SAM3U Series
4/8/12 MHz Fast RC Oscillator
Figure 27-3
Figure 27-3. Main Clock Block Diagram
The Main Clock has two sources:
After reset, the 4/8/12 MHz Fast RC Oscillator is enabled with the 4 MHz frequency selected and
it is selected as the source of MAINCK. MAINCK is the default clock selected to start up the
system.
The Fast RC Oscillator 8 and 12 MHz frequencies are calibrated in production. Note that is not
the case for the 4 MHz frequency.
Please refer to the “DC Characteristics” section of the product datasheet.
The software can disable or enable the 4/8/12 MHz Fast RC Oscillator with the MOSCRCEN bit
in the Clock Generator Main Oscillator Register (CKGR_MOR).
The user can also select the output frequency of the Fast RC Oscillator: either 4 MHz, 8 MHz or
12 MHz are available. It can be done through MOSCRCF bits in CKGR_MOR. When changing
• 4/8/12 MHz Fast RC Oscillator which starts very quickly and is used at startup
• 3 to 20 MHz Crystal Oscillator, which can be bypassed
Slow Clock
shows the Main Clock block diagram.
XOUT
SLCK
XIN
MOSCRCEN
MOSCRCEN
3-20 MHz Crystal
MOSCXTCNT
Main Clock
MOSCXTEN
4/8/12 MHz
MOSCXTEN
Frequency
3-20 MHz
Oscillator
Oscillator
Oscillator
Fast RC
Counter
Counter
Crystal
MOSCRCF
MOSCSEL
MAINRDY
MOSCRCS
MOSCXTS
MOSCSEL
MAINF
1
0
Main Clock
MOSCSELS
MAINCK
6430D–ATARM–25-Mar-11