DS2155LB Maxim Integrated, DS2155LB Datasheet - Page 72

• Manufacturer Part Number: DS2155LB
• Description: Network Controller & Processor ICs
• Manufacturer: Maxim Integrated

Bit 3/Local Loopback (LLB). In this loopback, data continues to be transmitted as normal through the transmit
side of the SCT. Data being received at RTIP and RRING are replaced with the data being transmitted. Data in this
loopback passes through the jitter attenuator. See
Bit 4/Line Interface Unit Mux Control (LIUC). This is a software version of the LIUC pin. When the LIUC pin
is connected high, the LIUC bit has control. When the LIUC pin is connected low, the framer and LIU are
separated and the LIUC bit has no effect
Bits 5 to 7/Unused, must be set to 0 for proper operation
LIUC Pin
0
0
1
1
0 = loopback disabled
1 = loopback enabled
0 = if LIUC pin connected high, LIU internally connected to framer block and deactivate the
TPOSI/TNEGI/TCLKI/RPOSI/RNEGI/RCLKI pins
1 = if LIUC pin connected high, disconnect LIU from framer block and activate the
TPOSI/TNEGI/TCLKI/RPOSI/RNEGI/RCLKI pins
LIUC Bit
0
1
0
1
LIU and framer separated
LIU and framer separated
LIU and framer connected
LIU and framer separated
Condition
Figure 3-2
72 of 238
for more details.