Dac Channel B Volume Control - Address 0Bh; Volume Control (Bits 7:0); Dac Control 2 - Address 0Ch; Dac Soft Ramp Or Zero Cross Enable (Bits 7:6) - Cirrus Logic CS4265 Manual

6.11

DAC Channel B Volume Control - Address 0Bh

7 6
Vol7 Vol6

6.11.1 Volume Control (Bits 7:0)

Function:
The digital volume control allows the user to attenuate the signal in 0.5 dB increments from 0 to -127 dB.
The Vol0 bit activates a 0.5 dB attenuation when set, and no attenuation when cleared. The Vol[7:1] bits
activate attenuation equal to their decimal equivalent (in dB). Example volume settings are decoded as
shown in Table
Cross bits in the DAC Control 2 register (see
6.12

DAC Control 2 - Address 0Ch

7 6
DACSoft DACZero

6.12.1 DAC Soft Ramp or Zero Cross Enable (Bits 7:6)

Function:
Soft Ramp Enable
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.
See Table 17.
Zero Cross Enable
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. See
Soft Ramp and Zero Cross Enable
Soft Ramp and Zero Cross Enable dictate that signal-level changes, either by attenuation changes or mut-
ing, will occur in 1/8 dB steps and be implemented on a signal zero crossing. The 1/8 dB 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 sam-
42
5 4
Vol5 Vol4
16. The volume changes are implemented as dictated by the DACSoft and DACZero-
Binary Code
00000000
00000001
00101000
00101001
11111110
11111111

Table 16. Digital Volume Control Example Settings

5 4
InvertDAC Reserved
Table 17.
3 2
Vol3 Vol2
Section 6.12.1).
Volume Setting
0 dB
-0.5 dB
-20 dB
-20.5 dB
-127 dB
-127.5 dB
3 2
Reserved Reserved
CS4265
1 0
Vol1 Vol0
1 0
Reserved Reserved
DS657F3