XRT74L73 Datasheet, PDF (182/488 Pages) Exar Corporation – 3 CHANNEL, ATM UNI/PPP DS3/E3 FRAMING CONTROLLER

XRT74L73
3 CHANNEL, ATM UNI/PPP DS3/E3 FRAMING CONTROLLER
REV. P1.0.1
PRELIMINARY
FIGURE 49. A SIMPLE ILLUSTRATION OF THE TRANSMIT SECTION, WITHIN THE XRT74L73, WHEN IT HAS BEEN CON-
FIGURED TO OPERATE IN THE DS3 MODE
TxOHFrame
TxOHEnable
TxOH
TxOHClk
TxOHIns
TxOHInd
TxSer
TxNib[2:0]
TxInClk
TxNibClk
TxFrame
TxNibFrame
TxFrameRef
Transmit
OverhTeraadnsInmpitut
InOtevrfearcheeaBdloIcnkput
Interface Block
Transmit
PaylToaradnDsmatiat
PaIynlpouatd Data
InterfacIenpBultock
Interface Block
Transmit DS3/E3
FTrraamnsemr Bit lDocSk3/E3
Framer Block
Transmit LIU
TInrtaenrfsamceit LIU
BInlotecrkface
Block
TxPOS
TxNEG
TxLineClk
From Microprocessor
Interface Block
Transmit DS3
TrHanDsLmCit DS3
ControlHleDr/BLCuffer
Controller/Buffer
Each of these functional blocks will be discussed in
detail in this document.
4.2.1 The Transmit Payload Data Input Inter-
face Block
Figure 50 presents a simple illustration of the Trans-
mit Payload Data Input Interface block.
FIGURE 50. A SIMPLE ILLUSTRATION OF THE TRANSMIT PAYLOAD DATA INPUT INTERFACE BLOCK
TxOH_Ind
TxSer
TxNib[2:0]
TxInClk
TxNibClk
TxNibFrame
TxFrame
TxFrameRef
Transmit
Payload Data
Input Interface
Block
To Transmit DS3
Framer Block
Each of the input and output pins of the Transmit Pay-
load Data Input Interface are listed in Table 34 and
described below. The exact role that each of these
inputs and output pins assume, for a variety of oper-
ating scenarios, are described throughout this sec-
tion.
183