CDB42438 Cirrus Logic Inc, CDB42438 Datasheet - Page 46

• Manufacturer Part Number: CDB42438
• Description: Eval Bd 108dB 6&8ch Multi-Chnl CODECs
• Manufacturer: Cirrus Logic Inc

Specifications of CDB42438

• Main Purpose: Audio, CODEC
• Embedded: Yes, FPGA / CPLD
• Utilized Ic / Part: CS42438
• Primary Attributes: 6 Single-Ended and 2 Differential Analog Inputs and 8 Outputs, S/PDIF Transmitter and Receiver
• Secondary Attributes: Graphic User Interface
• Description/function: Audio CODECs
• Operating Supply Voltage: 5 V to 12 V
• Product: Audio Modules
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: CS42438
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant, Contains lead / RoHS non-compliant
• Other names: 598-1500

46
7.7.2
7.7.3
The individual channel volume levels are independently controlled by their respective Volume Control reg-
isters when this function is disabled. When enabled, the volume on all channels is determined by the
AOUT1 and AIN1 Volume Control register and the other Volume Control registers are ignored.
Soft Ramp and Zero Cross Control (ADC_SZC[1:0], DAC_SZC[1:0])
Default = 00
00 - Immediate Change
01 - Zero Cross
10 - Soft Ramp
11 - Soft Ramp on Zero Crossings
Function:
Immediate Change
When Immediate Change is selected, all volume-level changes will take effect immediately in one step.
Zero Cross
Zero Cross Enable dictates that signal level changes, either by gain changes, attenuation changes or mut-
ing, will occur on a signal zero crossing to minimize audible artifacts. The requested level change will oc-
cur after a timeout 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
Soft Ramp allows level changes, either by gain changes, attenuation changes or muting, to be implement-
ed by incrementally ramping, 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.
Soft Ramp on Zero Crossing
Soft Ramp and Zero Cross Enable dictates that signal level changes, either by gain changes, attenuation
changes or muting, 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 timeout 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 inde-
pendently monitored and implemented for each channel.
Auto-Mute (AMUTE)
Default = 1
0 - Disabled
1 - Enabled
Function:
The Digital-to-Analog converters of the CS42438 will mute the output following the reception of 8192 con-
secutive audio samples of static 0 or -1. A single sample of non-static data will release the mute. Detection
and muting is done independently for each channel. The quiescent voltage on the output will be retained
during the mute period. The muting function is affected, similar to volume control changes, by the Soft and
Zero Cross bits (SZC[1:0]).
CS42438
DS646F2