AT32UC3L-EK Atmel, AT32UC3L-EK Datasheet - Page 189

• Manufacturer Part Number: AT32UC3L-EK
• Description: KIT EVAL AVR32 UC3 MCU
• Manufacturer: Atmel
• Type: MCUr

Specifications of AT32UC3L-EK

• Contents: *
• Silicon Manufacturer: Atmel
• Core Architecture: AVR
• Core Sub-architecture: UC3L
• Kit Contents: Board
• Features: USB / Battery Powered, Board Controller / Bootloader
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• Tool Type: Starter Kit
• Cpu Core: AVR 8
• Data Bus Width: 8 bit
• Processor Series: AT32
• Processor To Be Evaluated: AT32UC3L064
• Interface Type: USB, Capacitive Touch
• For Use With/related Products: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

32099F–11/2010
Coarse Value bit (DFLLnLOCKC) in PCLKSR will be set when this is done. In the FINE stage the
control logic tunes the value in DFLLnCONF.FINE so the output frequency will be very close to
the desired frequency. DFLLn Locked on Fine Value bit (DFLLnLOCKF) in PCLKSR will be set
when this is done. In the ACCURATE stage the DFLL frequency tuning mechanism uses dither-
ing on the FINE bits to obtain an accurate average output frequency. DFLLn Locked on Accurate
Value bit (DFLLnLOCKA) in PCLKSR will be set when this is done. The ACCURATE stage will
only be executed if the Dithering Enable bit (DITHER) in DFLLnCONF has been written to a one.
If DITHER is written to a zero DFLLnLOCKA will never occur. If dithering is enabled, the fre-
quency of the dithering is decided by a generic clock (CLK_DFLLIF_DITHER). This clock has to
be set up correctly before enabling dithering. Please refer to the Generic Clocks section for
details.
Figure 13-2. DFLL Closed-Loop State Diagram
When dithering is enabled the accuracy of the average output frequency of the DFLL will be
higher. However, the actual frequency will be alternating between two frequencies. If a fixed fre-
quency is required, the dithering should not be enabled.
DFLLnLOCKC
Calculate
COARSE
Measure
value
f
new
DFLLn
0
1
DFLLnLOCKF
new FINE
Calculate
value
0
1
Compen-
DITHER
sate for
drift
0
AT32UC3L016/32/64
1
DFLLnLOCKA
Calculate
dutycycle
dithering
new
0
1
Compen-
sate for
drift
189