AK4564 Datasheet, PDF (40/48 Pages) Asahi Kasei Microsystems – 16BIT CODEC WITH BUILT-IN ALC AND MIC/HP/SPK-AMP

ASAHI KASEI
[AK4564]
ALC Mode Control 1
Addr
Register Name
07H ALC Mode Control 1
Default
D7
D6
D5
D4
D3
D2
D1
D0
0
GSEL FDATT1 FDATT0 RGAIN1 RGAIN0 LMAT1 LMAT0
0
0
0
0
0
0
0
0
LMAT1-0: ALC1 Limiter ATT Step
The IVOL value is attenuated when the input signal exceeds the ALC1 limiter detection level. The number
of step to attenuate is decided by output level.
LMAT1
0
0
1
1
LMAT0
0
1
0
1
ALC1Limiter ATT Step
ALC1 Output ALC1 Output ALC1 Output
≥ LMTH
≥ FS
≥ FS + 6dB
1
1
1
2
2
2
2
2
4
2
4
4
Table 18. ALC1 Limiter ATT Step
ALC1 Output
≥ FS + 12dB
1
Default
2
4
8
RGAIN1-0: ALC1 Recovery GAIN Step
During the ALC1 recovery operation, the number of steps changed from current IVOL value is set. For
example, when the current IVOL value is 30H, RGAIN1-0= “01” are set, IVOL changes to 32H by the
auto limiter operation, the input signal level is gained by 0.75dB (=0.375dB x 2).
When the IVOL value exceeds the reference level (REF7-0), the IVOL value does not increase.
RGAIN1 RGAIN0 GAIN STEP
0
0
1
0
1
2
1
0
3
1
1
4
Table 19. ALC1 Recovery GAIN Step
Default
FDATT1-0: FADEIN/OUT ATT Step Setting
During the FADEIN/OUT operation, the number of steps changed from current IVOL value is set.
FDATT1 FDATT0 ATT STEP
0
0
1
Default
0
1
2
1
0
3
1
1
4
Table 20. FADEIN/OUT ATT Step Setting
GSEL: Select IVOL gain
0: MIC (Default)
1: LINE
MS0140-E-01
- 40 -
2002/07