Adc Input Control - Address 09H; Pga Soft Ramp Or Zero Cross Enable (Bits 4:3); Analog Input Selection (Bit 0); Dac Channel A Volume Control - Address 0Ah - Cirrus Logic CS4265 Manual

6.9

ADC Input Control - Address 09h

7 6
Reserved Reserved
6.9.1

PGA Soft Ramp or Zero Cross Enable (Bits 4:3)

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 14.
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-
ple rate) if the signal does not encounter a zero crossing. The zero cross function is independently mon-
itored and implemented for each channel. See
PGASoft
0
0
1
1
6.9.2 Analog Input Selection
Function:
These bits are used to select the input source for the PGA and ADC. Please see
6.10

DAC Channel A Volume Control - Address 0Ah

See 6.11 DAC Channel B Volume Control - Address
DS657F3
5 4
Reserved PGASoft
Table 14.
PGAZeroCross
0 Changes to affect immediately
1 Zero Cross enabled
0 Soft Ramp enabled
1 Soft Ramp and Zero Cross enabled (default)

Table 14. PGA Soft Cross or Zero Cross Mode Selection

(Bit 0)
Select
0
1

Table 15. Analog Input Selection

3 2
PGAZero Reserved
Table 14.
Mode
PGA/ADC Input
Microphone-Level Input
Line-Level Input
0Bh.
CS4265
1 0
Reserved Select
Table 15.
41