AT32UC3A4128 Atmel Corporation, AT32UC3A4128 Datasheet - Page 40

• Manufacturer Part Number: AT32UC3A4128
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A4128

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• Hardware Qtouch Acquisition: No
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Sd / Emmc: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• Dram Memory: No
• 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: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

6. Boot Sequence
6.1
6.2
32072G–11/2011
Starting of Clocks
Fetching of Initial Instructions
This chapter summarizes the boot sequence of the AT32UC3A3/A4. The behavior after power-
up is controlled by the Power Manager. For specific details, refer to
(PM)” on page
After power-up, the device will be held in a reset state by the Power-On Reset circuitry, until the
power has stabilized throughout the device. Once the power has stabilized, the device will use
the internal RC Oscillator as clock source.
On system start-up, the PLLs are disabled. All clocks to all modules are running. No clocks have
a divided frequency, all parts of the system receives a clock with the same frequency as the
internal RC Oscillator.
After reset has been released, the AVR32 UC CPU starts fetching instructions from the reset
address, which is 0x8000_0000. This address points to the first address in the internal Flash.
The internal Flash uses VDDIO voltage during read and write operations. It is recommended to
use the BOD33 to monitor this voltage and make sure the VDDIO is above the minimum level
(3.0V).
The code read from the internal Flash is free to configure the system to use for example the
PLLs, to divide the frequency of the clock routed to some of the peripherals, and to gate the
clocks to unused peripherals.
When powering up the device, there may be a delay before the voltage has stabilized, depend-
ing on the rise time of the supply used. The CPU can start executing code as soon as the supply
is above the POR threshold, and before the supply is stable. Before switching to a high-speed
clock source, the user should use the BOD to make sure the VDDCORE is above the minimum-
level (1.62V).
41.
Section 7. ”Power Manager
40