DS26521L+ Maxim Integrated Products, DS26521L+ Datasheet - Page 133

• Manufacturer Part Number: DS26521L+
• Description: IC TXRX T1/E1/J1 64-LQFP
• Manufacturer: Maxim Integrated Products
• Type: Line Interface Units (LIUs)r

Specifications of DS26521L+

• Number Of Drivers/receivers: 1/1
• Protocol: T1/E1/J1
• Voltage - Supply: 3.135 V ~ 3.465 V
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Product: Framer
• Number Of Transceivers: 1
• Data Rate: 44.736 Mbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Supply Current (max): 220 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Register Name:
Register Description:
Register Address:
Bit #
Name
Default
Bit 5: RSER Control (RSERC).
Bit 1: Payload Loopback (PLB).
When PLB is enabled, the following will occur:
In a PLB situation, the DS26521 loops the 192 bits (248 for E1) of payload data (with BPVs corrected) from the
receive section back to the transmit section. The transmitter follows the frame alignment provided by the receiver.
The receive frame boundary is automatically fed into the transmit section, such that the transmit frame position is
locked to the receiver (i.e., TSYNC is sourced from RSYNC). The FPS framing pattern, CRC-6 calculation, and the
FDL bits (FAS word, Si, Sa, E bits, and CRC-4 for E1) are not looped back. Rather, they are reinserted by the
DS26521 (i.e., the transmit section will modify the payload as if it was input at TSER).
Bit 0: Framer Loopback (FLB).
This loopback is useful in testing and debugging applications. In FLB, the DS26521 loops data from the transmit
side back to the receive side. When FLB is enabled, the following will occur:
1) Data will be transmitted from the TTIP and TRING pins synchronous with RCLK instead of TCLK.
2) All the receive-side signals will continue to operate normally.
3) The TCHCLK and TCHBLK signals are forced low.
4) Data at the TSER, TDATA, and TSIG pins is ignored.
5) The TLCLK signal will become synchronous with RCLK instead of TCLK.
1) (T1 mode) An unframed all-ones code will be transmitted at TTIP and TRING.
2) Data at RTIP and RRING will be ignored.
3) All receive-side signals will take on timing synchronous with TCLK instead of RCLK.
4) Note that it is not acceptable to have RCLK tied to TCLK during this loopback because this will cause an
0 = allow RSER to output data as received under all conditions (normal operation)
1 = force RSER to one under loss of frame alignment conditions
0 = loopback disabled
1 = loopback enabled
0 = loopback disabled
1 = loopback enabled
(E1 mode) Normal data will be transmitted at TTIP and TRING.
unstable condition.
—
7
0
RCR3
Receive Control Register 3
083h
—
6
0
RSERC
5
0
133 of 258
—
4
0
—
3
0
DS26521 Single T1/E1/J1 Transceiver
—
2
0
PLB
1
0
FLB
0
0