mt90502ag2 Zarlink Semiconductor, mt90502ag2 Datasheet - Page 92

• Manufacturer Part Number: mt90502ag2
• Description: Multi-channel Aal2 Sar
• Manufacturer: Zarlink Semiconductor

2.9.3
Complex silence suppression eliminates the external resource requirement to determine silent byte or silent packet.
The MT90502 analyses both the remote (Rx direction) and local (Tx direction) signals and evaluates if silence is to
be suppressed. The remote and local signals are processed to determine their average dB value over a
CPS-Packet. The mean average dB of the CPS-Packet for both directions are employed to identify the transmission
state as defined in the user configurable State Graph (Figure 52 on page 92).
Complex Silent Suppression
Local Energy
-Index = (((-Local Energy) *128)+(-Remote Energy)) where the local and Remote
Energies range from 0 to -78 dBm0 inclusively.
Index refers to S[index]
-The S State is defined as ‘00’=voice; ‘01’=transition - maintain the status of the last
non-transitional packet; ‘10’=silence; ‘11’=reserved.
Figure 52 - Complex Silent Suppression Configurable State Graph
TDM Data Byte
Match Value
Match Result
(1 = Mismatch)
Mask Value
Mask Result
(1 = mismatched cell)
Result
For each bit, result = (match XOR header) AND mask
-48 dBm0
0 dBm0
-78 dBm0
Figure 51 - Silent Suppression Mask & Match Example
+7FE
+0
- Index = (((-Local Envergy) *128) + (-Remote Energy)) where the Local and
Remote Energies range from 0 to -78 dBm0 inclusively.
- The S State is defined as “00” = voice; “01” = transition; “10” = silence; “11” =
reserved.
b 15
S[16376]
S[0]
Typical Silence Suppression State Table:
b14
-48 dBm0
Silence Suppression State Table
Voice
b13
S[16377]
S[1]
b12
Zarlink Semiconductor Inc.
b11
S[16378]
MT90502
Remote Energy
S[2]
b10
Silence
Considered Silent
92
1 0 1 1 0 0 1 0
1 0 1 1 0 0 1 0
0 0 0 0 0 0 0 0
1 1 1 1 1 1 1 1
0 0 0 0 0 0 0 0
S[16379]
b9
S[3]
b8
Transition
S[16380]
b7
S[4]
b6
S[16381]
b5
S[5]
0 dBm0
b4
1 0 1 1 0 1 1 0
1 0 1 1 0 0 1 0
0 0 0 0 0 1 0 0
1 1 1 1 1 1 1 1
0 0 0 0 0 1 0 0
S[16382]
b3
Not Silent
S[6]
b2
S[16383]
b1
S[7]
b0
silent2.cdd
Data Sheet