XRT72L52 Datasheet, PDF (1/480 Pages) Exar Corporation – TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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PRELIMINARY
XRT72L52
JANUARY 2001
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.3
GENERAL DESCRIPTION
The XRT72L52, 2 Channel DS3/E3 Framer IC is de-
signed to accept “User Data” from the Terminal
Equipment and insert this data into the “payload” bit-
fields within an “outbound” DS3/E3 Data Stream. Fur-
ther, the Framer IC is also designed to receive an “in-
bound” DS3/E3 Data Stream (from the Remote Ter-
minal Equipment) and extract out the “User Data”.
The XRT72L52 DS3/E3 Framer device is designed to
support full-duplex data flow between Terminal Equip-
ment and an LIU (Line Interface Unit) IC. The Framer
Device will transmit, receive and process data in the
DS3-C-bit Parity, DS3-M13, E3-ITU-T G.751 and E3-
ITU-T G.832 Framing Formats.
The XRT72L52 DS3/E3 Framer IC consists of two
Transmit sections, two Receiver sections, two Perfor-
mance Monitor Sections and a Microprocessor inter-
face.
The Transmit Sections, include a Transmit Payload
Data Input Interface, a Transmit Overhead data Input
Interface Section, a Transmit HDLC Controller, a
Transmit DS3/E3 Framer block and a Transmit LIU In-
terface Block which permits the Terminal Equipment
to transmit data to a remote terminal.
The Receive Sections, consist of a Receive LIU Inter-
face, a Receive DS3/E3 Framer, a Receive HDLC
Controller, a Receive Payload Data Output Interface,
and a Receive Overhead Data Interface which allows
the local terminal equipment to receive data from re-
mote terminal equipment.
The Microprocessor Interface is used to configure the
Framer IC in different operating modes and monitor
the performance of the Framer.
The Performance Monitor Sections consist of a large
number of "Reset-upon-Read" and "Read-Only" reg-
isters that contain cumulative and "one-second" sta-
tistics that reflect the performance/health of the two
channels of the Framer IC/system.
FEATURES
• Transmits, Receives and Processes data in the
DS3-C-bit Parity, DS3-M13, E3-ITU-T G.751 and
E3-ITU-T G.832 Framing Formats.
• 2 Channel HDLC Controller - Tx and Rx
• Interfaces to all Popular Microprocessors
• Integrated Framer Performance Monitor
• Available in a 160 Pin PQFP package
• 3.3V Power Supply with 5V Tolerant I/O
• Operating Temperature -40°C to +85°C
APPLICATIONS
• Network Interface Units
• CSU/DSU Equipment.
• PCM Test Equipment
• Fiber Optic Terminals
• DS3/E3 Frame Relay Equipment
FIGURE 1. BLOCK DIAGRAM OF THE XRT72L52
Reset
TestMode
NibbleLnTF
TxOHEnable
TxOHClk
TxOHFrame
TxAISEn
TxOH
TxOHIns
T3/E3
Transmit
Overhead
Interface
TxLineClk[n:0]
TxPOS[n:0]
TxNEG[n:0]
RxLineClk[n:0]
RxPOS[n:0]
RxNEG[n:0]
ExtLOS
RxOHEnable[n:0]
RxOHClk[n:0]
RxOH[n:0]
RxRed[n:0]
RxOHFrame[n:0]
RxOOF[n:0]
LIU
Interface/
Controller
T3/E3
Receive
Overhead
Interface
Typical Channel n
Where n = 0 or 1
T3/E3 Transmit
Framer
T3/E3
transmit
Input
T3 FEAC & Data
Link Controller
Performance
Monitor
Interrupt
Controller
T3/E3 Receive
Framer
T3/E3
Receive
Output
HDLC
controller
uP
Interface
HDLC
controller
TxOHInd[n:0]
TxNibFrame[n:0]
TxFrame[n:0]
TxNibClk[n:0]
TxLnClk[n:0]
TxFrameRef[n:0]
TxNib[n:0]
TxSer[n:0]
A(11:0)
D(7:0)
ALE_AS
WR_R/W
CS
RDY_DTCK
Reset
INT
MOTO
RD_DS
RxClk[n:0]
RxOHind[n:0]
RxFrame[n:0]
RxNib[n:0]
RxSer[n:0]
RxOUTClk[n:0]
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com