txc-03456 TranSwitch Corporation, txc-03456 Datasheet - Page 58

• Manufacturer Part Number: txc-03456
• Description: Device Level Mapper
• Manufacturer: TranSwitch Corporation

140 Mbit/s Line Interface
Figure 26 is a simplified view of the 140 Mbit/s line interface. The NIB control lead selects whether the receive
and transmit line interface is nibble- or byte-wide. The AIS clock (AISCK) should be connected to a stable
34.816 MHz frequency source for nibble interface operation, or to a 17.408 MHz frequency source for byte
interface operation. The AIS indication lead (AISIND) provides an external indication when AIS is generated.
L4M
TXC-03456
AISIND
AISCK
RXCO
RXDn
CTRL
CTRL
TXDn
RXCI
TXC
NIB
23
21
14
15
24
71
74
87
Receive Clock Out
Receive Clock In
Figure 26. L4M 140 Mbit/s Line Interface
Loop Filter
AIS Indication
AIS Clock (as required)
Nibble/Byte Selection
Transmit Clock
Byte Data
Nibble or
Byte Data
Nibble or
DATA SHEET
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Interface
Interface
VCXO
CMI
CMI
Receive Serial Data
Transmit Serial Data
Ed. 1A, January 2000
TXC-03456
TXC-03456-MB
L4M