
XRT79L71
PRELIMINARY
53
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
REV. P2.0.0
4.0
ARCHITECTURAL/FUNCTIONAL DESCRIPTION OF THE XRT79L71 1-CHANNEL DS3/E3 ATM UNI/
PPP/CLEAR-CHANNEL FRAMER WITH LIU IC - CLEAR CHANNEL FRAMER AND HIGH-SPEED
HDLC CONTROLLER MODE APPLICATIONS
This particular document describes how to operate the XRT79L71 in both the DS3/E3 Clear-Channel Framer
Mode. If the XRT79L71 has been configured to operate in the DS3 Clear-Channel Framer Mode, then its
functional block diagram will be as depicted below in Figure 13.
Figure 13 indicates that whenever the XRT79L71 has been configured to operate in the DS3 Clear-Channel
Framer Mode, then all of the following blocks will become active.
The Transmit Payload Data Input Interface Block
The Transmit Overhead Data Input Interface Block
The Transmit FEAC Controller Block (DS3, C-bit Parity Applications Only)
The Transmit LAPD Controller Block (DS3, C-bit Parity 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 LAPD Controller Block (DS3, C-bit Parity Applications Only)
The Receive FEAC Controller Block (DS3, C-bit Parity Applications Only)
The Receive Overhead Data Output Interface Block
The Receive Payload Data Output Interface Block
The XRT79L71 can be configured to support any of the following framing formats.
DS3, C-bit Parity
DS3, M13 (also referred to as M23)
E3, ITU-T G.751
E3, ITU-T G.832
This document describes, (1) how to configure the XRT79L71 into each of these framing formats and (2) how
to use each of the features within the XRT79L71.
This section discusses "DS3 Clear-Channel Framer"
ITU-T G.832 Clear-Channel Framer" Applications, respectively.
Prior to going into the details of Clear-Channel Framer operations of the XRT79L71, the user is advised that
the XRT79L71 can also be configured to support ATM over DS3/E3 Applications, PPP over DS3/E3
Applications, and finally High-Speed HDLC over DS3/E3 Applications. The Architectural Description for each
of these documents can be obtained separately and are listed below, by title.
XRT79L71ATM - Architectural Description of the XRT79L71 1-Channel DS3/E3 ATM UNI/PPP/Clear-
Channel Framer and LIU IC - ATM UNI Applications
XRT79L71PPP - Architectural Description of the XRT79L71 1-Channel DS3/E3 ATM UNI/PPP/Clear-
Channel Framer and LIU IC - PPP Applications
Figure 13. An Illustration of the Functional Block Diagram of the XRT79L71 when it has been config-
ured to operate in the DS3 Clear-Channel Framer Mode