xr
PRELIMINARY
XRT86VL38
REV. P1.0.6
OCTAL T1/E1/J1 FRAMER/LIU COMBO
322
5.1.6
Framer Local Loopback
With framer local loopback activated, the transmit PCM input data is looped back to the receive PCM output
data. The receive input data at RTIP/RRING is ignored while an All Ones Signal is transmitted out to the line
interface. A simplified block diagram of framer remote line loopback is shown in Figure 37.
F
IGURE
36. S
IMPLIFIED
B
LOCK
D
IAGRAM
OF
THE
F
RAMER
R
EMOTE
L
INE
L
OOPBACK
F
IGURE
37. S
IMPLIFIED
B
LOCK
D
IAGRAM
OF
THE
F
RAMER
L
OCAL
L
OOPBACK
Encoder
Decoder
Timing
Control
Data and
Clock
Recovery
JA
JA
Tx
Rx
TAOS
NLC/PRBS/QRSS
TTIP
TRING
RTIP
RRING
Framer
Tx
Framer
Rx
Tx Serial
Clock
Rx Serial
Clock
ST
-BUS
2-Frame
Slip Buffer
Elastic Store
Tx Serial
Data In
Tx LIU
Interface
2-Frame
Slip Buffer
Elastic Store
Rx LIU
Interface
Rx Framer
Rx Serial
Data Out
Tx Framer
LLB