WM5102 Datasheet, PDF (248/334 Pages) Wolfson Microelectronics plc – Audio Hub CODEC with Voice Processor DSP

WM5102
Production Data
SPREAD SPECTRUM FLL CONTROL
The WM5102 can apply modulation to the FLL outputs, using spread spectrum techniques. This can
be used to control the EMI characteristics of the circuits that are clocked via the FLLs.
Each of the FLLs can be individually configured for Triangle modulation, Zero Mean Frequency
Modulation (ZMFM) or Dither. The amplitude and frequency parameters of the spread spectrum
functions is also programmable, using the registers described in Table 107.
REGISTER BIT
ADDRESS
LABEL
DEFAULT
DESCRIPTION
R393
(0189h)
FLL1
Spread
Spectrum
5:4 FLL1_SS_AMPL
[1:0]
00
FLL1 Spread Spectrum Amplitude
Controls the extent of the spread-
spectrum modulation.
00 = 0.7% (triangle), 0.7% (ZMFM, dither)
01 = 1.1% (triangle), 1.3% (ZMFM, dither)
10 = 2.3% (triangle), 2.6% (ZMFM, dither)
11 = 4.6% (triangle), 5.2% (ZMFM, dither)
3:2 FLL1_SS_FREQ
[1:0]
00
FLL1 Spread Spectrum Frequency
Controls the spread spectrum modulation
frequency in Triangle mode.
00 = 439kHz
01 = 878kHz
10 = 1.17MHz
11 = 1.76MHz
1:0 FLL1_SS_SEL
[1:0]
00
FLL1 Spread Spectrum Select
00 = Disabled
01 = Triangle
10 = Zero Mean Frequency (ZMFM)
11 = Dither
R425
(01A9h)
FLL2
Spread
Spectrum
5:4 FLL2_SS_AMPL
[1:0]
00
FLL2 Spread Spectrum Amplitude
Controls the extent of the spread-
spectrum modulation.
00 = 0.7% (triangle), 0.7% (ZMFM, dither)
01 = 1.1% (triangle), 1.3% (ZMFM, dither)
10 = 2.3% (triangle), 2.6% (ZMFM, dither)
11 = 4.6% (triangle), 5.2% (ZMFM, dither)
3:2 FLL2_SS_FREQ
[1:0]
00
FLL2 Spread Spectrum Frequency
Controls the spread spectrum modulation
frequency in Triangle mode.
00 = 439kHz
01 = 878kHz
10 = 1.17MHz
11 = 1.76MHz
1:0 FLL2_SS_SEL
[1:0]
00
FLL2 Spread Spectrum Select
00 = Disabled
01 = Triangle
10 = Zero Mean Frequency (ZMFM)
11 = Dither
Table 107 FLL Spread Spectrum Control
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PD, June 2014, Rev 4.2
248