Cirrus Logic CS4271 - Manual (Page 39)

CS4271
DS592F1 39
8.2 DAC Control - Address 02h
8.2.1 Auto-Mute (Bit 7)
Function:
When set, enables the Auto-Mute function. See “Auto-Mute” on page 30.
8.2.2 Interpolation Filter Select (Bit 6)
Function:
This Function allows the user to select whether the Interpolation Filter has a fast or slow roll off. When
set, this bit selects the slow roll off filter, when cleared it selects the fast roll off filter. The - 3 dB corner
is approximately the same for both filters, but the slope of the roll off is greater for the fast roll off filter.
8.2.3 De-Emphasis Control (Bits 5:4)
Function:
Implementation of the standard 50/15
µs digital de-emphasis filter response, Figure 19, requires re-
configuration of the digital filter to maintain the proper filter response for 32, 44.1 or 48 kHz sample
rates. NOTE: De-emphasis is available only in Single-Speed Mode. See Table 13 below.
7 6 5 4 3 2 1 0
AMUTE FILT_SEL DEM1 DEM0 RMP_UP RMP_DN INV_A INV_B
Table 13. De-Emphasis Mode Selection
DEM1 DEM0 Description
0 0 Disabled (default)
0 1 44.1 kHz de-emphasis
1 0 48 kHz de-emphasis
1 1 32 kHz de-emphasis
Gain
dB
-10dB
0dB
Frequency
T2 = 15 µs
T1=50 µs
F1 F2
3.183 kHz 10.61 kHz
Figure 19. De-Emphasis Curve