ak4141 AKM Semiconductor, Inc., ak4141 Datasheet - Page 91

• Manufacturer Part Number: ak4141
• Description: Nicam/a2/eia-j Digital Stereo Decoder
• Manufacturer: AKM Semiconductor, Inc.

SNST[7:0]
AVCH[7:0], AVCL[7:0]
MS0952-E-00
Addr
Addr
Addr
93H
94H
95H
The NICAM Noise SCS threshold is used by the stereo carrier search function to determine the quality based on
received symbol phase error. This 8-bit threshold is compared against the top 8 bits of the NICAM noise value.
These two thresholds are used to control the target audio level when AVC is active. AVC works by maintaining the
combined power of the left and right channels between these high and low level thresholds. The output volume, in dB,
relative to full scale is:
The values of these registers should not exceed 128.
SNSTh = Average Symbol Phase Error Magnitude (degrees) * 32 / 22.5 (degrees)
NICAM Noise SCS Threshold
AVC Level Threshold High
AVC Level Threshold Low
Register Name
Register Name
Register Name
Default
Default
Default
R/W
R/W
R/W
Error Magnitude (degrees)
Average Symbol Phase
Table 109.Typical NICAM Noise ASD Threshold Values
21.1
22.5
179
7.0
0
20*log10(threshold/128)
D7
D7
D7
- 91 -
(decimal)
D6
SNST
D6
D6
255
10
30
32
0
D5
D5
D5
(Recommended)
(default)
AVCH[7:0]
AVCL[7:0]
SNST[7:0]
1111 1111
0010 0110
0001 1011
D4
D4
D4
R/W
R/W
R/W
D3
D3
D3
D2
D2
D2
D1
D1
D1
[AK4141]
2008/05
D0
D0
D0