XRT79L71_07 Datasheet, PDF (60/109 Pages) Exar Corporation – 1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - HARDWARE

XRT79L71
1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - HARDWARE
REV. 1.0.0
FIGURE 2. THE FUNCTIONAL BLOCK DIAGRAM OF THE XRT79L71 WHEN IT HAS BEEN CONFIGURED TO OPERATE IN
THE CLEAR-CHANNEL DS3/E3 FRAMER MODE
TxOHFrame
TxOHEnable
TxOH
TxOHClk
TxOHIns
TxOHInd
TxSer
TxNib[3:0]
TxInClk
TxNibClk
TxFrame
MOTO
D[7:0]
A[8:0]
IntB*
CSB*
RdB_DS
WrB_RW
Rdy_Dtck
Reset*
ALE_AS
RxOHInd
RxSer
RxNib[3:0]
RxOutClk
RxNibClk
RxFrame
RxOHFrame
RxOH
RxOHClk
RxOHEnable
Transmit Overhead
Input
Interface Block
Transmit Payload
Data Input
Interface Block
Transmit DS3/E3
Framer Block
Microprocessor
Interface
Receive Payload
Data Output
Interface Block
Receive Overhead
Output
Interface Block
Tx LAPD Buffer/
Controller
Rx LAPD Buffer/
Controller
Receive DS3/E3
Framer Block
DDSS33/E/E33
JJitittetrer
AAtttetnenuuaatotror
BBlolockck
TTrarannsmsmitit
DDSS33/E/E33
LLIUIUBBlolockck
TTIP
TRING
Only one JA exists.
Can be configured in
Tx or Rx Path
DDSS33/E/E33
JJitittetrer
AAtttetnenuuaatotror
BBlolockck
RReceecievive _e
DDSS33/E/E33
LLIUIUBBlolockck
RTIP
RRING
Figure 2 indicates that the XRT79L71 consists of the following functional blocks.
• The Transmit Payload Data Input Interface Block
• The Transmit Overhead Data Input Interface Block
• The Transmit LAPD Controller Block
• The Transmit FEAC Controller Block (DS3, C-bit Parity Applications Only)
• The Transmit Trail-Trace Message Controller Block (E3, ITU-T G.832 Applications Only)
• The Transmit SSM Controller Block (E3, ITU-T G.832 Applications Only)
• The Transmit DS3/E3 Framer Block
• The Transmit DS3/E3 LIU Block
• The Receive DS3/E3 LIU Block
• The Receive DS3/E3 Framer Block
• The Receive SSM Controller Block (E3, ITU-T G.832 Applications Only)
• The Receive Trail-Trace Message Controller Block (E3, ITU-T G.832 Applications Only)
• The Receive FEAC Controller Block (DS3, C-bit Parity Applications Only)
• The Receive LAPD Controller Block
• The Receive Payload Data Output Interface Block
• The Receive Overhead Data Output Interface Block
Each of these functional blocks is briefly discussed below. These functional blocks will be discussed in
considerable detail throughout this data sheet.
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