SAM3U2C Atmel Corporation, SAM3U2C Datasheet - Page 333

• Manufacturer Part Number: SAM3U2C
• Manufacturer: Atmel Corporation

Specifications of SAM3U2C

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 96 MHz
• Cpu: Cortex-M3
• # Of Touch Channels: 28
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 57
• Ext Interrupts: 57
• Usb Transceiver: 1
• Quadrature Decoder Channels: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device
• Spi: 4
• Twi (i2c): 1
• Uart: 4
• Ssc: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 36
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 1.62 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

23. SAM3U4/2/1 Boot Program
23.1
23.2
23.3
6430E–ATARM–29-Aug-11
Description
Flow Diagram
Device Initialization
The SAM-BA
into the different memories of the product.
The Boot Program implements the algorithm in
Figure 23-1. Boot Program Algorithm Flow Diagram
The SAM-BA Boot program seeks to detect a source clock either from the embedded main oscil-
lator with external crystal (main osccillator enabled) or from a 12 MHz signal applied to the XIN
pin (Main oscillator in bypass mode).
If a clock is found from the two possible sources above, the boot program checks to verify that
the frequency is 12 MHz (taking into account the frequency range of the 32 kHz RC oscillator). If
the frequency is 12 MHz, USB activation is allowed, else (no clock or frequency other than
12MHz), the internal 12 MHz RC oscilator is used as main clock and USB clock is not allowed
due to frequency drift of the 12 MHz RC oscillator.
Initialization follows the steps described below:
1. Stack setup
2. Setup the Embedded Flash Controller
3. External Clock detection (Quartz or external clock on XIN)
4. If Quartz or external clock is 12.000 MHz, allow USB activation
5. Else, does not allow USB activation and use internal RC 12 MHz
6. Main oscillator frequency detection if no external clock detected
7. Switch Master Clock on Main Oscillator
8. C variable initialization
9. PLLA setup: PLLA is initialized to generate a 48 MHz clock
10. UPLL setup in case of USB activation allowed
11. Disable of the Watchdog
12. Initialization of the UART (115200 bauds, 8, N, 1)
13. Initialization of the USB Device Port (in case of USB activation allowed)
14. Wait for one of the following events
®
Device
Setup
Boot Program integrates an array of programs permitting download and/or upload
Run SAM-BA Monitor
USB Enumeration
Successful ?
Yes
Figure
23-1.
No
Run SAM-BA Monitor
Character # received
No
from UART?
SAM3U Series
Yes
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