DS21Q55N Maxim Integrated Products, DS21Q55N Datasheet - Page 76

• Manufacturer Part Number: DS21Q55N
• Description: Framer E1/J1/T1 3.3V 256-Pin BGA
• Manufacturer: Maxim Integrated Products

Specifications of DS21Q55N

• Package: 256BGA
• Number Of Transceivers: 4
• Standard Framing Format: E1|J1|T1
• Maximum Supply Current: 75(Typ) mA
• Minimum Single Supply Voltage: 3.135 V
• Maximum Single Supply Voltage: 3.465 V

Bit 3/Local Loopback (LLB). In this loopback, data continues to be transmitted as normal through the transmit
side of the device. 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
76 of 237
Figure 1-2
for more details.