Cirrus Logic CS53L21 - Manual (Page 53)

DS700PP1 53
CS53L21
Function:
Sets the rate at which the ALC releases the PGA & digital attenuation from levels below the minimum setting
in the ALC threshold register, and returns the input level to the PGA_VOL[4:0] & ADCx_ATT[7:0] setting.
The ALC release rate is user selectable, but is also a function of the sampling frequency, Fs, and the SOFTx
& ZCROSS bit settings unless the disable bit for each function is enabled.
6.15 ALC Threshold (Address 1Eh)
Maximum Threshold (MAX[2:0])
Default: 000
Function:
Sets the maximum level, relative to full scale, at which to limit and attenuate the input signal at the attack
rate.
Minimum Threshold (MIN[2:0])
Default: 000
Function:
Sets the minimum level at which to disengage the ALC’s attenuation or amplify the input signal at a rate set
in the release rate register until levels again reach this minimum threshold. The ALC uses this minimum as
a hysteresis point for the input signal as it maintains the signal below the maximum as well as below the
minimum setting. This provides a more natural sound as the ALC attacks and releases.
7 6 5 4 3 2 1 0
MAX2 MAX1 MAX0 MIN2 MIN1 MIN0 Reserved Reserved
MAX[2:0] Threshold
Setting
(dB)
000 0
001 -3
010 -6
011 -9
100 -12
101 -18
110 -24
111 -30
MIN[2:0]
Threshold
Setting
(dB)
000 0
001 -3
010 -6
011 -9
100 -12
101 -18
110 -24
111 -30