xrt91l31 Exar Corporation, xrt91l31 Datasheet - Page 6

• Manufacturer Part Number: xrt91l31
• Description: Sts-12/stm-4 Or Sts-3/stm-1 Sonet/sdh Transceiver
• Manufacturer: Exar Corporation

XRT91L31
STS-12/STM-4 OR STS-3/STM-1 SONET/SDH TRANSCEIVER
PIN DESCRIPTIONS
PIN DESCRIPTION
CMUFREQSEL
CDR_BW/VDD
STS12/STS3
RESET
N
AME
LVCMOS
LVCMOS
LVCMOS
LVCMOS
LVTTL,
LVTTL,
LVTTL,
LVTTL,
L
EVEL
T
YPE
I
I
I
I
T
ABLE
P
59
15
1
3
IN
2: H
ARDWARE
Master Reset Input
Active "High." When this pin is pulled "High" , the internal state
machines are set to their default state.
"Low" = Normal Operation
"High" = Master Hardware Reset
Data Rate Selection
Selects SONET/SDH transmission and reception speed rate
"Low" = STS-3/STM-1 155.52 Mbps
"High" = STS-12/STM-4 622.08 Mbps
Clock Multiplier Unit Reference Frequency Select
This pin is used to select the frequency of the REFCLKP/N or
TTLREFCLK input to the CMU.
"Low" = 77.76 MHz reference clock
"High" = 19.44 MHz reference
clock
N
CDR Bandwidth Select
This pin is used to select the CDR Bandwidth
"Low" = Narrow BW, (Meets SONET jitter transfer requirement)
"High" (VDD) = Wide Band Width.
FREQSEL
OTE
6
CMU-
: REFCLKP/N or TTLREFCLK input should be generated
0
0
1
1
from an LVPECL/LVTTL crystal oscillator which has a
frequency accuracy better than 20ppm in order for the
transmitted data rate frequency to have the necessary
accuracy required for SONET systems..
C
ONTROL
STS12/
STS3
0
1
0
1
D
REFCLKP/N
ESCRIPTION
TTLREFCLK
FREQUENCY
REFERENCE
77.76 MHz
77.76 MHz
19.44 MHz
19.44 MHz
OR
STS-12/STM-4
STS-12/STM-4
STS-3/STM-1
STS-3/STM-1
155.52 Mbps
622.08 Mbps
155.52 Mbps
622.08 Mbps
D
ATA
R
REV. 1.0.0
ATE