AK4536 Datasheet, PDF (54/59 Pages) Asahi Kasei Microsystems – 16-Bit Mono CODEC with ALC & MIC/SPK-AMP

ASAHI KASEI
[AK4536]
n MIC Input Recording
FS2-0 bits _XXX
(Addr:05H,D2-0)
(1)
MIC Control
(Addr:02H,D2-0)
001
(2)
ALC1 Control
1
(Addr:06H)
ALC1 Control
2
(Addr:08H)
ALC1 Control
3
(Addr:09H)
ALC1 Control
4
(Addr:07H)
ALC1 State
XXH
(3)
XXH
(4)
XXH
(5)
XXH
(6)
ALC1 Disable
XXX
X1X
Example:
PLL Master Mode
Audio I/F Format:DSP Mode, BCKP=MSBS=“0”
Sampling Frequency:8kHz
Pre MIC AMP:+20dB
MIC Power On
ALC1 setting:Refer to Figrure 28
ALC2 bit=“1”(default)
(1) Addr:05H, Data:00H
00H
(2) Addr:02H, Data:07H
47H
(3) Addr:06H, Data:00H
47H
(4) Addr:08H, Data:47H
61H or 21H
ALC1 Enable ALC1 Disable
(5) Addr:09H, Data:47H
(6) Addr:07H, Data:61H
PMADC bit
(Addr:00H,D0)
PMMIC bit
(Addr:00H,D1)
ADC Internal
State
(7) Addr:00H, Data:43H
(7)
(8)
1059 / fs
Recording
Power Down
Initialize Normal State Power Down
(8) Addr:00H, Data:40H
Figure 38. MIC Input Recording Sequence
<Example>
This sequence is an example of ALC1 setting at fs=8kHz. If the parameter of the ALC1 is changed, please refer to
“Figure 28. Register set-up sequence at the ALC1 operation.”
At first, clocks should be supplied according to “Clock Set Up” sequence.
(1) Set up a sampling frequency (FS2-0 bits). When the AK4536 is PLL mode, MIC and ADC should be powered-up
in consideration of PLL lock time after a sampling frequency is changed.
(2) Set up MIC input (Addr: 02H)
(3) Set up Timer Select for ALC1 (Addr: 06H)
(4) Set up REF value for ALC1 (Addr: 08H)
(5) Set up IPGA value for ALC1 (Addr: 09H)
(6) Set up LMTH, RATT, LMAT1-0, ALC1 bits (Addr: 07H)
(7) Power Up MIC and ADC: PMMIC bit = PMADC bit = “0” → “1”
The initialization cycle time of ADC is 1059/fs=133ms@fs=8kHz.
After the ALC1 bit is set to “1” and MIC block is powered-up, the ALC1 operation starts.
(8) Power Down MIC and ADC: PMMIC bit = PMADC bit = “1” → “0”
When the registers for the ALC1 operation are not changed, ALC1 bit may be keeping “1”. The ALC1 operation
is disabled because the MIC block is powered-down. If the registers for the ALC1 operation are also changed
when the sampling frequency is changed, it should be done after the AK4536 goes to the manual mode (ALC1 bit
= “0”) or MIC block is powered-down (PMMIC bit = “0”).
MS0174-E-00
- 54 -
2002/09