XRT84L38IB Exar Corporation, XRT84L38IB Datasheet - Page 378

• Manufacturer Part Number: XRT84L38IB
• Description: Network Controller & Processor ICs 8 Ch T1/E1 Framer
• Manufacturer: Exar Corporation

Specifications of XRT84L38IB

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XRT84L38
OCTAL T1/E1/J1 FRAMER
When the Transmit Data Conditioning Select [3:0] bits of the Transmit Channel Control Register (TCCR) of a
particular DS0 channel are set to 0100, input E1 PCM data of this DS0 channel are replaced by the octet
stored in User IDLE Code Register (UCR). The table below shows contents of the User IDLE Code Register.
USER IDLE CODE REGISTER (UCR) (INDIRECT ADDRESS = 0XN02H, 0X20H - 0X3FH)
11.4
Each 256-bit E1 frame is divided into 32 octets or time slots numbered 0 to 31. Each time slot is a 64kbits/s
channel carrying voice or data information. The time slot 0 is used for frame and multi-frame synchronization,
CRC-4 error detection, yellow alarm transmission and data link transmission. The time slot 1 to time slot 15
and time slot 17 to time slot 31 are used to carry a PCM encoded voice band signal or data. The remaining
64kbits/s channel time slot 16 may be used for signaling. The XRT84L38 T1/J1/E1 Octal Framer supports the
following signaling formats to interconnect to CEPT channelized service functions:
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•
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The XRT84L38 T1/J1/E1 Octal Framer supports insertion of various types of signaling information into the
timeslot 16 of an outgoing E1 frame. It also supports extraction and substitution of signaling information from
the incoming E1 frame. The following section provides a brief overview of Common Channel Signaling,
Channel Associated Signaling in E1 mode.
N
11.4.1
As the name referred, Common Channel Signaling is signaling information common to all thirty voice or data
channels of an E1 trunk. The time slot 16 may be used to carry Common Channel Signaling data of up to a rate
of 64kbits/s. The national bits of time slot 0 may also be used for Common Channel Signaling. Since there are
five national bits of time slot 0 per every two E1 frames, the total bandwidth of the national bits is 20kbits/s. The
Common Channel Signaling is essentially data link information that provides performance monitoring and
transmission quality report.
11.4.2
Signaling is required when dealing with voice and dial-up data services in E1 applications. Traditionally,
signaling is provided on a dial-up telephone line, across the talk-path. Signaling is used to tell the receiver
where the call or route is destined. The signal is sent through switches along the route to a distant end.
Common types of signals are:
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•
•
•
•
OTE
N
Common Channel Signaling (CCS)
Channel Associated Signaling (CAS)
Primary Rate ISDN Message Oriented Signaling (ISDN-PRI)
On hook
Off hook
Dial tone
Dialed digits
Ringing cycle
UMBER
B
7-0
: The time slot 16 can also be configured to carry PCM encoded voice or data if neither CCS nor CAS signaling is
IT
used. The XRT84L38 framer allows the user to choose which one of the CCS, CAS, ISDN-PRI message or PCM
data to be carries on the time slot 16.
How to Configure the XRT84L38 Framer to Transmit Signaling Information
Brief Discussion of Channel Associated Signaling in E1 Framing Format
Brief Discussion of Common Channel Signaling in E1 Framing Format
User IDLE Code
B
IT
N
AME
B
IT
R/W
T
YPE
These READ/WRITE bit-fields permits the user store any value of IDLE
code into the framer. When the Transmit Data Conditioning Select [3:0] bits
of TCCR register of a particular DS0 channel are set to 0100, the input E1
PCM data are replaced by contents of this register and sent to the Trans-
mit LIU Interface.
358
B
IT
D
ESCRIPTION
REV. 1.0.1