Datasheet

236
42023E–SAM–07/2013
ATSAM4L8/L4/L2
13.7.14 DFLLx Spread Spectrum Generator Control Register
Name: DFLLxSSG
Access Type: Read/Write
Reset Value: 0x00000000
• STEPSIZE: SSG Step Size
Selects the step size of the spread spectrum. If zero or one, the value added to the FINE bits will be incremented/decremented
with one on every positive edge of the input clock. If n > 1, the value added to the FINE bits will be incremented/decremented
with n on every positive edge of the input clock.
• AMPLITUDE: SSG Amplitude
Selects the amplitude of the spread spectrum. If zero, only the LSB of the FINE bits will be affected. If one, the sequence {1, 0,
-1, 0} will be added to FINE bits, etc.
• PRBS: Pseudo Random Bit Sequence
0: Each spread spectrum frequency is applied at constant intervals
1: Each spread spectrum frequency is applied at pseudo-random intervals
• EN: Enable
0: SSG is disabled.
1: SSG is enabled.
Note that this register is protected by a lock. To write to this register the UNLOCK register has to be written first. Refer to
Section 13.7.7 ”Unlock Register” on page 228 for details.
31 30 29 28 27 26 25 24
-
-------
23 22 21 20 19 18 17 16
- - - STEPSIZE
15 14 13 12 11 10 9 8
- - - AMPLITUDE
76543210
------PRBSEN