4 interpolation filter, 5 system clocking, Table 1. clock ratios – Cirrus Logic CS4392 User Manual

Page 10: 4 interpolation filter 3.5 system clocking, Cs4392

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CS4392

10

DS459PP3

3.4

Interpolation Filter

To accommodate the increasingly complex requirements of digital audio systems, the CS4392 incorpo-
rates selectable interpolation filters for each mode of operation. A fast and a slow roll-off filter is available
in each of Single, Double, and Quad Speed modes. These filters have been designed to accommodate a
variety of musical tastes and styles. Bit 5 of the Mode Control 3 register (06h) is used to select which filter
is used. Filter specifications can be found in Section 8, and filter response plots can be found in Figures 12
to

35.

In stand-alone mode, only the fast roll-off filter is available.

3.5

System Clocking

The required MCLK to LRCK and suggested SCLK to LRCK ratios are outlined in table 1. MCLK can be
at any phase in regards to LRCK and SCLK. SCLK, LRCK and SDATA must meet the phase and timing
relationships outlined in Section 7. Some common MCLK frequencies have been outlined in tables 2 to 4.

*Note:These clocking ratios are only available in Control Port Mode when the MCLK Divide bit is enabled.

MCLK/LRCK

SCLK/LRCK

LRCK

Single Speed

256, 384, 512, 768, 1024*

32, 48, 64, 96, 128

Fs

Double Speed

128, 192, 256, 384, 512*

32, 48, 64

Fs

Quad Speed

64

32 (16 bits only)

Fs

96

32, 48

Fs

128, 256*

32, 64

Fs

192

32, 48, 64, 96

Fs

Table 1. Clock Ratios

Sample Rate

(kHz)

MCLK (MHz)

See Note

256x

384x

512x

768x

1024x*

32

8.1920

12.2880

16.3840

24.5760

32.7680

44.1

11.2896

16.9344

22.5792

33.8688

45.1584

48

12.2880

18.4320

24.5760

36.8640

49.1520

Table 2. Single Speed (4 to 50 kHz sample rates) Common Clock Frequencies

Sample Rate

(kHz)

MCLK (MHz)

See Note

128x

192x

256x

384x

512x*

64

8.1920

12.2880

16.3840

24.5760

32.7680

88.2

11.2896

16.9344

22.5792

33.8688

45.1584

96

12.2880

18.4320

24.5760

36.8640

49.1520

Table 3. Double Speed (50 to 100 kHz sample rates) Common Clock Frequencies

Sample Rate

(kHz)

MCLK (MHz)

See Note

64x

96x

128x

192x

256x*

176.4

11.2896

16.9344

22.5792

33.8688

45.1584

192

12.2880

18.4320

24.5760

36.8640

49.1520

Table 4. Quad Speed (100 to 200 kHz sample rates) Common Clock Frequencies

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