XRT91L34IV-F View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT91L34IV-F' PDF : 38 Pages View PDF
XRT91L34
QUAD CHANNEL MULTIRATE STS-12/3/1 AND STM-4/1/0 SONET/SDH CDR
REV. 1.0.1
1.0 FUNCTIONAL DESCRIPTION
The XRT91L34 Quad Channel CDR is designed to operate with a multichannel SONET Framer/ASIC device
and provide a high-speed serial clock and data recovery interface to optical networks. The CDR receives
differential NRZ serial bit stream running at STS-12/STM-4 or STS-3/STM-1 or STS-1/STM-0, and outputs
recovered serial clock and data via differential LVDS/LVPECL drivers. It implements four independently
configurable receive clock and data recovery (CDR) units and a LOL and LOS detection circuit (Host Mode
Only) for each channel. The CDR is used to provide the front end component of SONET equipment.
1.1 Hardware Mode vs. Host Mode
Functional control of the receiver can be configured by using either Host mode or Hardware mode. Hardware
mode is selected by pulling HOST/HW "Low" or leaving this pin unconnected. The receiver functionality is then
controlled by the hardware pins described in the Hardware Pin Descriptions. Host mode is selected by pulling
HOST/HW "High". In Host mode the functionality is controlled by programming internal R/W registers using the
Serial Microprocessor interface. Host mode offers functions not available in Hardware mode, such as Loss of
Signal Monitoring, Interrupt Generation and Disabling of the recovered clock output.
1.2 STS-12/STM-4 and STS-3/STM-1 and STS-1/STM-0 Mode of Operation
The data rate of each receiver channel can be configured by using the appropriate signal level on the
DATAnRATE1:0] pins (where n = channel 0, 1, 2, or 3) as shown in Table 1.
TABLE 1: CHANNEL DATA RATE SELECTION
DATANRATE[1:0]
0
0
0
1
1
0
1
1
DATA RATE SELECTED FOR
CHANNEL N
STS-1/STM-0
51.84 Mbps
STS-3/STM-1
155.52 Mbps
STS-12/STM-4
622.08 Mbps
STS-12/STM-4
622.08 Mbps
NOTE: n denotes channel number.
12
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