PSB4860HV4.1 Lantiq, PSB4860HV4.1 Datasheet - Page 61

• Manufacturer Part Number: PSB4860HV4.1
• Manufacturer: Lantiq

Specifications of PSB4860HV4.1

• Lead Free Status / Rohs Status: Supplier Unconfirmed

The coder can optionally use silence gap coding. This feature can reduce the bit rate
dramatically if there are long periods of silence in the incoming data stream. The GAP
bit in the STATUS register is set when a gap is detected and the speech coder performs
gap coding. This feature is only available for compression rates 5.6 and 10.3 kBit/s, and
thus cannot be used to influence compression rate in 3.3 kBit/s mode.
Furthermore the speech coder contains a VOX detector that can distinguish voice from
signals with constant energy (noise, silence, sine signals). The result of this detector is
available by the bit VOX of the STATUS register.
Table 31
Register # of Bits
STATUS 1
STATUS 1
STATUS 1
The operation of the speech coder is defined according to table 32.
Table 32
Register # of Bits
SCCTL
SCCTL
SCCTL
SCCTL
SCCTL
SCCTL
SCCTL
SCCT2
SCCT2
SCCT3
SCCT3
Data Sheet
1
1
2
1
1
5
5
8
8
7
8
Speech Coder Status
Speech Coder Control Registers
Name
SD
GAP
VOX
Name
EN
GAP
Q0, Q1
VC
VOX
I1
I2
MIN
TIME
LP
GAPT
Comment
Speech detected
A gap is detected during recording
Noise, silence, constant or periodic signal detected
Comment
Enable speech coder
Enable gap coding
Recording quality
Voice controlled recording
Minimal signal level for speech detection
Minimum time for reset of SD
Time constant for low-pass
Minimum time for gap
VOX detection enable
Input signal 1 selection
Input signal 2 selection
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PSB 4860
2000-01-14