XRT72L56 Datasheet, PDF (478/486 Pages) Exar Corporation – SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L56
SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.2
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PRELIMINARY
7 (Local Loop-back) within the Framer Operating
Mode Register, as illustrated below.
FRAMER OPERATING MODE REGISTER (ADDRESS = 0X00)
BIT 7
Local Loopback
BIT 6
DS3/E3*
R/W
R/W
1
X
BIT 5
Internal
LOS
Enable
R/W
X
BIT 4
RESET
BIT 3
Interrupt
Enable Reset
BIT 2
Frame Format
R/W
R/W
R/W
0
X
X
BIT 1
BIT 0
TimRefSel[1:0]
R/W
R/W
X
X
NOTES:
1. When the XRT72L56 DS3/E3 Framer IC is operat-
ing in the Framer Local-Loop-back Mode, no data
will be output via the TxPOS and TxNEG output
pins.
2. The XRT72L56 DS3/E3 Framer IC cannot be con-
figured to operate in the Framer Local Loop-back
Mode, if it is configured to operate in Modes 1 or
Mode 4 (Loop-Timing Modes). The user must con-
figure the XRT72L56 Framer to operate in one of
the Local-Timing modes.
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