zl50211 Zarlink Semiconductor, zl50211 Datasheet - Page 9

• Manufacturer Part Number: zl50211
• Description: 256 Channel Voice Echo Canceller
• Manufacturer: Zarlink Semiconductor

The following description applies to a single EVP (Echo Voice Processor). Note that the ZL50211 contains eight
EVP’s.
1.0
Each single Echo Voice Processor (EVP) contains 32 echo cancellers divided into 16 groups. Each group has two
echo cancellers, Echo Canceller A (ECA) and Echo Canceller B (ECB). Each group can be configured in Normal,
Extended Delay or Back-to-Back configurations. In Normal configuration, a group of echo cancellers provides two
channels of 64 ms echo cancellation, which run independently on different channels. In Extended Delay
configuration, a group of echo cancellers achieves 128 ms of echo cancellation by cascading the two echo
cancellers (A & B). In Back-to-Back configuration, the two echo cancellers from the same group are positioned to
cancel echo coming from both directions in a single channel, providing full-duplex 64 ms echo cancellation.
Each Echo Voice Processor contains the following main elements (see Figure 4).
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SG1, SG2, SG3, SG4,
SG5, SG6, SG7, SG8
DT1, DT2, DT3, DT4,
DT5, DT6, DT7, DT8
AT1, AT2, AT3, AT4,
AT5, AT6, AT7, AT8
Adaptive Filter for estimating the echo channel
Subtractor for cancelling the echo
Double-Talk detector for disabling the filter adaptation during periods of double-talk
Path Change detector for fast reconvergence on major echo path changes
Instability Detector to combat instability in very low ERL environments
Patented Advanced Non-Linear Processor for suppression of residual echo, with comfort noise injection
Disable Tone Detectors for detecting valid disable tones at send and receive path inputs
Narrow-Band Detector for preventing Adaptive Filter divergence from narrow-band signals
Offset Null filters for removing the DC component in PCM channels
0 to -12 dB level adjusters at all signal ports
Parallel controller interface compatible with Motorola microcontrollers
PCM encoder/decoder compatible with µ/A-Law ITU-T G.711 or Sign-Magnitude coding
T1M1, T1M2, T1M3,
T1M4, T1M5, T1M6,
T2M4, T2M5, T2M6,
T2M1, T2M2, T2M3,
Signal Name
Single Echo Voice Processor (EVP) Description
T1M7, T1M8
T2M7, T2M8
PLL Test
PLL Test
PLL Test
PLL Test
PLL Test
Signals
Signals
Signals
Signals
Signals
Signal
Type
AD3,AF25,B18,A18
D1,AH26,E1,AE1,
F2,AG25,G3,AF1,
G2,AF23,G1,AF2,
G4,AJ25,F1,AE2,
AD4,AK22,D18,
AH2,AJ1,AG20,
AE4,AJ24,D17,
AH25,B17,C17
K4,AJ20,J1,
BGA Ball #
F28,F26
AG1,
Zarlink Semiconductor Inc.
C18
A17
ZL50211
9
Internal Connection. Connected to VSS for normal
operation.
Internal Connection. Connected to VSS for normal
operation.
Internal Connection. Connected to VSS for normal
operation.
No connection. These pins must be left open for
normal operation.
No connection. These pins must be left open for
normal operation.
Signal Description
Data Sheet