Table 16. example digital volume settings, 6 ramp and filter control - register 07h, Cs4349 – Cirrus Logic CS4349 User Manual
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DS782F2
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CS4349
8.5
Channel A & B Volume Control - Register 05h & 06h
Digital Volume Control (VOL[7:0])
Bits 7-0
Default = 00h (0 dB)
Function:
The Digital Volume Control registers allow independent control of the signal levels in 1/2 dB increments
from 0 to -127.5 dB. Volume settings are decoded as shown in
. The volume changes are imple-
mented as dictated by the Soft and Zero Cross bits in the Power and Muting Control register. The actual
attenuation is determined by taking the decimal value of the volume register and multiplying by 6.02/12.
8.6
Ramp and Filter Control - Register 07h
8.6.1
Soft Ramp and Zero Cross Control (SZC[1:0]) Bits 7-6
Default = 10
Function:
Immediate Change
When Immediate Change is selected, all level changes will take effect immediately in one step.
Zero Cross
Zero Cross Enable dictates that signal level changes, either by attenuation changes or muting, will occur
on a signal zero crossing to minimize audible artifacts. The requested level change will occur after a time-
out period between 512 and 1024 sample periods (10.7 ms to 21.3 ms at 48 kHz sample rate) if the signal
does not encounter a zero crossing. The zero cross function is independently monitored and implemented
for each channel.
Soft Ramp PCM
Soft Ramp allows level changes, both muting and attenuation, to be implemented by incrementally ramp-
ing, in 1/8 dB steps, from the current level to the new level at a rate of 1 dB per 8 left/right clock periods.
7
6
5
4
3
2
1
0
VOL7
VOL6
VOL5
VOL4
VOL3
VOL2
VOL1
VOL0
0
0
0
0
0
0
0
0
Table 16. Example Digital Volume Settings
Binary Code
Decimal Value
Volume Setting
00000000
0
0 dB
00000001
1
-0.5 dB
00000110
6
-3.0 dB
11111111
255
-127.5 dB
7
6
5
4
3
2
1
0
SZC1
SZC0
RMP_UP
RMP_DN
Reserved
FILT_SEL
Reserved
Reserved
1
0
1
1
0
0
0
1
SZC1 SZC0
Description
0
0
Immediate Change
0
1
Zero Cross
1
0
Soft Ramp
1
1
Soft Ramp on Zero Crossings