
ASAHI KASEI
[AK4640]
MS0273-E-00
2004/03
- 55 -
Addr
08H
Register Name
Timer Select
R/W
Default
D7
0
RD
0
D6
D5
ZTM1
R/W
0
D4
ZTM0
R/W
0
D3
D2
D1
LTM1
R/W
0
D0
LTM0
R/W
0
ROTM
R/W
0
WTM1
R/W
0
WTM0
R/W
0
LTM1-0: ALC1 limiter operation period at zero crossing disable (see Table 25)
The IPGA value is changed immediately. When the IPGA value is changed continuously, the change is done
by the period specified by the LTM1-0 bits. Default is “00” (0.5/fs).
ALC1 Limiter Operation Period
8kHz
63
μ
s
125
μ
s
250
μ
s
500
μ
s
Default
LTM1
LTM0
16kHz
31
μ
s
63
μ
s
125
μ
s
250
μ
s
44.1kHz
11
μ
s
23
μ
s
45
μ
s
91
μ
s
0
0
1
1
0
1
0
1
0.5/fs
1/fs
2/fs
4/fs
Table 25. ALC1 Limiter Operation Period at zero crossing disable (ZELM bit = “1”)
WTM1-0: ALC1 Recovery Waiting Period (see Table 26)
A period of recovery operation when any limiter operation does not occur during the ALC1 operation.
Default is “00” (128/fs).
ALC1 Recovery Operation Waiting Period
8kHz
128/fs
16ms
256/fs
32ms
512/fs
64ms
1024/fs
128ms
Table 26. ALC1 Recovery Operation Waiting Period
Default
WTM1
WTM0
16kHz
8ms
16ms
32ms
64ms
44.1kHz
2.9ms
5.8ms
11.6ms
23.2ms
0
0
1
1
0
1
0
1
ZTM1-0: Zero crossing timeout for the write operation by the
μ
P, ALC1 recovery, and zero crossing enable (ZELM
bit = “0”) of the ALC1 operation (see Table 27)
When the IPGA performs zero crossing or timeout, the IPGA value is changed by the
μ
P WRITE operation,
ALC1 recovery operation or ALC1 limiter operation (ZELM bit = “0”).
Default is “00” (128/fs).
Zero Crossing Timeout Period
8kHz
16ms
32ms
64ms
128ms
Table 27. Zero Crossing Timeout Period
Default
ZTM1
ZTM0
16kHz
8ms
16ms
32ms
64ms
44.1kHz
2.9ms
5.8ms
11.6ms
23.2ms
0
0
1
1
0
1
0
1
128/fs
256/fs
512/fs
1024/fs
ROTM:
0: 2048/fs (Default)
1: 512/fs
Period time for ALC2 Recovery operation