
XRT84L38
374
OCTAL T1/E1/J1 FRAMER
REV. 1.0.1
CAS Selection [1:0] bits of the Framing Select Register (FSR) enable the framer to search for CAS Multi-frame
alignment.
The table below shows configurations of the CAS Selection [1:0] bit of the Framing Select Register (FSR).
12.3
How to Configure the Framer to Apply Data and Signaling Conditioning to Received E1 Payload
Data on a Per-Channel Basis
The XRT84L38 T1/J1/E1 Octal Framer provides individual control of each of the thirty two DS0 channels. The
user can apply data and signaling conditioning to the received E1 payload data coming from the E1 LIU
Receive Block on a per-channel basis.
The XRT84L38 framer can apply the following changes to the received E1 payload data coming from the
Terminal Equipment on a per-channel basis:
All 8 bits of the received payload data are inverted
The even bits of the received payload data are inverted
The odd bits of the received payload data are inverted
The MSB of the received payload data is inverted
All received payload data except the MSB are inverted
Configurations of the XRT84L38 framer to apply the above-mentioned changes to the received E1 PAYLOAD
data are controlled by the Receive Data Conditioning Select [3:0] bits of the Receive Channel Control Register
(RCCR) of each DS0 channel.
The XRT84L38 framer can also replace the incoming E1 payload data from the E1 LIU Receive Block with pre-
defined or user-defined codes. The XRT84L38 supports the following conditioning substitutions:
BUSY code - an octet with hexadecimal value of 0x7F
BUSY_TS code - an octet of pattern "111xxxxx" where "xxxxx" represents the timeslot number
VACANT code - an octet with hexadecimal value of 0xFF
A-law Digital Milliwatt code
FRAMING SELECT REGISTER (FSR) (INDIRECT ADDRESS = 0XN0H, 0X07H)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
5-4
CAS Selection bit
R/W
These Read/Write bit fields allow the user to enable searching of CAS
Multi-frame alignment and determine which algorithm of the two are used
for locking the CAS Multi-frame alignment pattern.
00 - Searching of CAS Multi-frame alignment is disabled. The XRT84L38
framer will not search for CAS Multi-frame alignment and thus will not
declare CAS Multi-frame synchronization. No Receive CAS Multi-frame
Synchronization (RxCRCMsync_n) pulse will be generated by the framer.
01 - Searching of CAS Multi-frame alignment is enabled. The XRT84L38
will search for and declare CAS Multi-frame synchronization using Algo-
rithm 1.
10 - Searching of CAS Multi-frame alignment is enabled. The XRT84L38
will search for and declare CAS Multi-frame synchronization using Algo-
rithm 2 (G.732).
11 - Searching of CAS Multi-frame alignment is disabled. The XRT84L38
framer will not search for CAS Multi-frame alignment and thus will not
declare CAS Multi-frame synchronization. No Receive CAS Multi-frame
Synchronization (RxCRCMsync_n) pulse will be generated by the framer.