XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. 1.0.1
5.1.6
Framer Payload Loopback
With framer payload loopback activated, the raw data within the receive time slots are looped back to the
transmit framer block where the data is re-framed according to the transmit timing. A simplified block diagram
of framer payload loopback is shown in Figure 32.
F
IGURE 32. SIMPLIFIED
B
LOCK
D
IAGRAM OF THE
F
RAMER
L
OCAL
L
OOPBACK
2-Frame
Slip Buffer
Elastic Store
Tx Serial
Data In
Tx LIU
Interface
Tx Framer
Rx Framer
Tx Serial
Clock
PLB
2-Frame
Slip Buffer
Elastic Store
Rx Serial
Data Out
Rx LIU
Interface
Rx Serial
Clock
5.1.7
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 33.
F
IGURE 33. SIMPLIFIED
B
LOCK
D
IAGRAM OF THE
F
RAMER
L
OCAL
L
OOPBACK
2-Frame
Slip Buffer
Elastic Store
Tx Serial
Data In
Tx LIU
Interface
Tx Framer
Rx Framer
Tx Serial
Clock
LLB
2-Frame
Slip Buffer
Elastic Store
Rx Serial
Data Out
Rx LIU
Interface
Rx Serial
Clock
159
EXAR [ EXAR CORPORATION ]
