xrt75r12 Exar Corporation, xrt75r12 Datasheet - Page 23

• Manufacturer Part Number: xrt75r12
• Description: Twelve Channel E3/ds3/sts-1 Line Interface Unit With Jitter
• Manufacturer: Exar Corporation

XRT75R12
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.4
2.1
Clock Distribution
Network cards that are designed to support multiple line rates which are not configured for single frequency
mode should ensure that a clock is applied to the DS3Clk input pin. For example: If the network card being
supplied to an ISP requires E3 only, the DS-3 input clock reference is still necessary to provide read and write
access to the internal microprocessor. Therefore, the E3 mode requires two input clock references. If
however, multiple line rates will not be supported, i.e. E3 only, then the DS3Clk input pin may be hard wire
connected to the E3Clk input pin.
F
4. C
D
C
E3 M
W
U
SFM
IGURE
LOCK
ISTRIBUTION
ONGIFURED IN
ODE
ITHOUT
SING
DS3Clk
E3Clk
CLKOUT_n
Clock Synthesizer
LOL_n
Processor
N
: For one input clock reference, the single frequency mode should be used.
OTE
20