áç
XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
DECEMBER 2004
REV. 1.0.0
GENERAL DESCRIPTION
attenuator performance meets the ETSI TBR-24 and
Bellcore GR-499 specifications.
The XRT75R06 is a six channel fully integrated Line
Interface Unit (LIU) featuring EXAR’s R3 Technology
(Reconfigurable, Relayless, Redundancy) for E3/
DS3/STS-1 applications. The LIU incorporates 6
independent Receivers, Transmitters and Jitter
Attenuators in a single 217 Lead BGA package.
Each channel of the XRT75R06 can be
independently configured to operate in E3 (34.368
MHz), DS3 (44.736 MHz) or STS-1 (51.84 MHz).
Each transmitter can be turned off and tri-stated for
redundancy support or for conserving power.
The XRT75R06’s differential receiver provides high
noise interference margin and is able to receive data
over 1000 feet of cable or with up to 12 dB of cable
attenuation.
The XRT75R06 incorporates an advanced crystalless jitter attenuator per channel that can be selected
either in the transmit or receive path. The jitter
The XRT75R06 provides a Parallel Microprocessor
Interface for programming and control.
The XRT75R06 supports analog, remote and digital
loop-backs. The device also has a built-in Pseudo
Random Binary Sequence (PRBS) generator and
detector with the ability to insert and detect single bit
error for diagnostic purposes.
APPLICATIONS
• E3/DS3 Access Equipment
• DSLAMs
• Digital Cross Connect Systems
• CSU/DSU Equipment
• Routers
• Fiber Optic Terminals
FIGURE 1. BLOCK DIAGRAM OF THE XRT 75R06
CS
RD
WR
Addr[7:0]
D[7:0]
PCLK
RDY
INT
XRT75R06
XRT75R06
SFM_en
RLOL_n
Pmode
RESET
RTIP_n
RRing_n
TRing_n
MTIP_n
MRing_n
DMO_n
ICT
Clock
Synthesizer
Peak Detector
AGC/
Equalizer
Slicer
Line
Driver
Device
Monitor
Clock & Data
Recovery
Jitter
Attenuator
LOS
Detector
Local
LoopBack
TTIP_n
CLKOUT_n
µProcessor Interface
MUX
HDB3/
B3ZS
Decoder
E3Clk
DS3Clk
STS-Clk/12M
RxClk_n
RxPOS_n
RxNEG/LCV_n
Remote
LoopBack
RLOS_n
Tx
Pulse
Shaping
Tx
Control
Timing
Control
Jitter
Attenuator
MUX
HDB3/
B3ZS
Encoder
TxClk_n
TxPOS_n
TxNEG_n
TxON
Channel 0
Channel n...
Channel 5
ORDERING INFORMATION
PART NUMBER
PACKAGE
OPERATING TEMPERATURE RANGE
XRT75R06IB
217 Lead BGA
-40°C to +85°C
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com
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XRT75R06
REV. 1.0.0
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
• Each channel supports Analog, Remote and Digital
FEATURES
Loop-backs
RECEIVER
• R3
Technology
Redundancy)
(Reconfigurable,
• Single 3.3 V ± 5% power supply
• 5 V Tolerant digital inputs
• Available in 217 pin BGA Package
• - 40°C to 85°C Industrial Temperature Range
Relayless,
• On chip Clock and Data Recovery circuit for high
input jitter tolerance
• Meets E3/DS3/STS-1 Jitter Tolerance Requirement
• Detects and Clears LOS as per G.775
• Receiver Monitor mode handles up to 20 dB flat
TRANSMIT INTERFACE CHARACTERISTICS
• Accepts either Single-Rail or Dual-Rail data from
Terminal Equipment and generates a bipolar signal
to the line
loss with 6 dB cable attenuation
• Integrated Pulse Shaping Circuit
• Built-in B3ZS/HDB3 Encoder (which can be
• On chip B3ZS/HDB3 encoder and decoder that can
be either enabled or disabled
• On-chip clock synthesizer provides the appropriate
disabled)
• Accepts Transmit Clock with duty cycle of 30%-
rate clock from a single 12.288 MHz Clock
• Provides low jitter output clock
70%
• Generates pulses that comply with the ITU-T G.703
TRANSMITTER
•R
3
Technology
Redundancy)
(Reconfigurable,
pulse template for E3 applications
Relayless,
• Generates pulses that comply with the DSX-3 pulse
template, as specified in Bellcore GR-499-CORE
and ANSI T1.102_1993
• Compliant with Bellcore GR-499, GR-253 and ANSI
T1.102 Specification for transmit pulse
• Generates pulses that comply with the STSX-1
• Tri-state Transmit output capability for redundancy
pulse template, as specified in Bellcore GR-253CORE
applications
• Each Transmitter can be independently turned on
• Transmitter can be turned off in order to support
or off
redundancy designs
• Transmitters provide Voltage Output Drive
RECEIVE INTERFACE CHARACTERISTICS
JITTER ATTENUATOR
• Integrated Adaptive Receive Equalization (optional)
• On chip advanced crystal-less Jitter Attenuator for
for optimal Clock and Data Recovery
each channel
• Declares and Clears the LOS defect per ITU-T
• Jitter Attenuator can be selected in Receive,
G.775 requirements for E3 and DS3 applications
Transmit path, or disabled
• Meets Jitter Tolerance Requirements, as specified
• Meets ETSI TBR 24 Jitter Transfer Requirements
• Compliant with jitter transfer template outlined in
in ITU-T G.823_1993 for E3 Applications
• Meets Jitter Tolerance Requirements, as specified
ITU G.751, G.752, G.755 and GR-499-CORE,1995
standards
in Bellcore GR-499-CORE for DS3 Applications
• Declares Loss of Lock (LOL) Alarm
• Built-in B3ZS/HDB3 Decoder (which can be
• 16 or 32 bits selectable FIFO size
CONTROL AND DIAGNOSTICS
disabled)
• Parallel Microprocessor Interface for control and
• Recovered Data can be muted while the LOS
configuration
• Supports
optional
Condition is declared
internal
Transmit
driver
• Outputs either Single-Rail or Dual-Rail data to the
monitoring
Terminal Equipment
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SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
FIGURE 2. XRT75R06 IN BGA PACKAGE (BOTTOM
VIEW)
(See pin list for pin names and function)
A
B
C
D
E
F
G
H
J
K
L
XRT75R06
M
N
P
R
T
U
17
16
15
14
12
12
11
10
9
3
8
7
6
5
4
3
2
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REV. 1.0.0
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
TABLE OF CONTENTS
GENERAL DESCRIPTION ................................................................................................. 1
APPLICATIONS ..............................................................................................................................................
Figure 1. Block Diagram of the XRT 75R06 ......................................................................................................
ORDERING INFORMATION ................................................................................................................... 1
FEATURES ....................................................................................................................................................
TRANSMIT INTERFACE CHARACTERISTICS ......................................................................................................
RECEIVE INTERFACE CHARACTERISTICS ........................................................................................................
Figure 2. XRT75R06 in BGA package (Bottom View) .......................................................................................
1
1
2
2
2
3
PIN DESCRIPTIONS (BY FUNCTION) ............................................................................. 4
TRANSMIT INTERFACE ................................................................................................................................... 4
RECEIVE INTERFACE ..................................................................................................................................... 6
CLOCK INTERFACE ........................................................................................................................................ 8
CONTROL AND ALARM INTERFACE ....................................................................................................... 9
ANALOG POWER AND GROUND ................................................................................................................... 12
DIGITAL POWER AND GROUND ..................................................................................................................... 14
FUNCTIONAL DESCRIPTION ......................................................................................... 16
1.0 R3 Technology (reconfigurable, relayless redundancy) ............................................................... 16
1.1 NETWORK ARCHITECTURE ................................................................................................................................ 16
Figure 3. Network Redundancy Architecture ................................................................................................. 16
2.0 clock Synthesizer ............................................................................................................................. 17
2.1 CLOCK DISTRIBUTION ....................................................................................................................................... 17
Figure 5. Clock Distribution Congifured in E3 Mode Without Using SFM .......................................................
Figure 4. Simplified Block Diagram of the Input Clock Circuitry Driving the Microprocessor ..........................
3.0 The Receiver Section .......................................................................................................................
Figure 6. Receive Path Block Diagram ...........................................................................................................
17
17
18
18
3.1 RECEIVE LINE INTERFACE ................................................................................................................................. 18
Figure 7. Receive Line InterfaceConnection ................................................................................................... 18
3.2 ADAPTIVE GAIN CONTROL (AGC) ..................................................................................................................... 19
3.3 RECEIVE EQUALIZER ........................................................................................................................................ 19
Figure 8. ACG/Equalizer Block Diagram ......................................................................................................... 19
3.3.1 Recommendations for Equalizer Settings .......................................................................................
3.4 CLOCK AND DATA RECOVERY ..........................................................................................................................
3.4.1 Data/Clock Recovery Mode ...............................................................................................................
3.4.2 Training Mode .....................................................................................................................................
3.5 LOS (LOSS OF SIGNAL) DETECTOR ..................................................................................................................
3.5.1 DS3/STS-1 LOS Condition .................................................................................................................
3.5.2 Disabling ALOS/DLOS Detection ......................................................................................................
19
19
19
19
20
20
20
TABLE 1: THE ALOS (ANALOG LOS) DECLARATION AND CLEARANCE THRESHOLDS FOR A GIVEN SETTING OF
LOSTHR AND REQEN (DS3 AND STS-1 APPLICATIONS) ................................................................... 20
3.5.3 E3 LOS Condition: ............................................................................................................................. 21
Figure 9. Loss Of Signal Definition for E3 as per ITU-T G.775 ....................................................................... 21
Figure 10. Loss of Signal Definition for E3 as per ITU-T G.775. ..................................................................... 21
3.5.4 Interference Tolerance ....................................................................................................................... 22
Figure 11. Interference Margin Test Set up for DS3/STS-1 ............................................................................ 22
Figure 12. Interference Margin Test Set up for E3. ......................................................................................... 22
TABLE 2: INTERFERENCE MARGIN TEST RESULTS .............................................................................................. 23
3.5.5 Muting the Recovered Data with LOS condition: ............................................................................ 24
3.6 B3ZS/HDB3 DECODER .................................................................................................................................... 24
Figure 13. Receiver Data output and code violation timing ............................................................................ 24
4.0 The Transmitter Section .................................................................................................................. 25
Figure 14. Transmit Path Block Diagram ........................................................................................................ 25
4.1 TRANSMIT DIGITAL INPUT INTERFACE ................................................................................................................ 25
Figure 15. Typical interface between terminal equipment and the XRT75R06 (dual-rail data) ....................... 25
Figure 16. Transmitter Terminal Input Timing ................................................................................................. 26
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Figure 17. Single-Rail or NRZ Data Format (Encoder and Decoder are Enabled) ......................................... 26
4.2 TRANSMIT CLOCK ............................................................................................................................................
4.3 B3ZS/HDB3 ENCODER ...................................................................................................................................
4.3.1 B3ZS Encoding ..................................................................................................................................
4.3.2 HDB3 Encoding ..................................................................................................................................
27
27
27
27
Figure 18. Dual-Rail Data Format (encoder and decoder are disabled) ......................................................... 27
Figure 19. B3ZS Encoding Format ................................................................................................................. 27
4.4 TRANSMIT PULSE SHAPER ............................................................................................................................... 28
Figure 21. Transmit Pulse Shape Test Circuit ................................................................................................ 28
4.4.1 Guidelines for using Transmit Build Out Circuit ............................................................................. 28
Figure 20. HDB3 Encoding Format ................................................................................................................ 28
4.5 E3 LINE SIDE PARAMETERS .............................................................................................................................. 29
Figure 22. Pulse Mask for E3 (34.368 mbits/s) interface as per itu-t G.703 ...................................................
TABLE 3: E3 TRANSMITTER LINE SIDE OUTPUT AND RECEIVER LINE SIDE INPUT SPECIFICATIONS ..........................
Figure 23. Bellcore GR-253 CORE Transmit Output Pulse Template for SONET STS-1 Applications .........
TABLE 4: STS-1 PULSE MASK EQUATIONS ........................................................................................................
TABLE 5: STS-1 TRANSMITTER LINE SIDE OUTPUT AND RECEIVER LINE SIDE INPUT SPECIFICATIONS (GR-253) .
Figure 24. Transmit Ouput Pulse Template for DS3 as per Bellcore GR-499 ................................................
TABLE 7: DS3 TRANSMITTER LINE SIDE OUTPUT AND RECEIVER LINE SIDE INPUT SPECIFICATIONS (GR-499) ....
TABLE 6: DS3 PULSE MASK EQUATIONS ...........................................................................................................
29
30
31
31
32
32
33
33
4.6 TRANSMIT DRIVE MONITOR .............................................................................................................................. 34
4.7 TRANSMITTER SECTION ON/OFF ....................................................................................................................... 34
Figure 25. Transmit Driver Monitor set-up. ..................................................................................................... 34
5.0 Jitter .................................................................................................................................................. 35
5.1 JITTER TOLERANCE .......................................................................................................................................... 35
5.1.1 DS3/STS-1 Jitter Tolerance Requirements ...................................................................................... 35
Figure 26. Jitter Tolerance Measurements ..................................................................................................... 35
5.1.2 E3 Jitter Tolerance Requirements .................................................................................................... 36
Figure 27. Input Jitter Tolerance For DS3/STS-1 .......................................................................................... 36
Figure 28. Input Jitter Tolerance for E3 ......................................................................................................... 36
5.2 JITTER TRANSFER ............................................................................................................................................ 37
5.3 JITTER ATTENUATOR ........................................................................................................................................ 37
TABLE 8: JITTER AMPLITUDE VERSUS MODULATION FREQUENCY (JITTER TOLERANCE) ....................................... 37
TABLE 9: JITTER TRANSFER SPECIFICATION/REFERENCES ................................................................................. 37
5.3.1 Jitter Generation ................................................................................................................................ 38
TABLE 10: JITTER TRANSFER PASS MASKS ....................................................................................................... 38
Figure 29. Jitter Transfer Requirements and Jitter Attenuator Performance .................................................. 38
6.0 Diagnostic Features ......................................................................................................................... 39
6.1 PRBS GENERATOR AND DETECTOR ................................................................................................................. 39
Figure 30. PRBS MODE ................................................................................................................................. 39
6.2 LOOPBACKS ................................................................................................................................................ 40
6.2.1 ANALOG LOOPBACK ........................................................................................................................ 40
Figure 31. Analog Loopback ........................................................................................................................... 40
6.2.2 DIGITAL LOOPBACK ......................................................................................................................... 41
6.2.3 REMOTE LOOPBACK ........................................................................................................................ 41
Figure 32. Digital Loopback ............................................................................................................................ 41
Figure 33. Remote Loopback ......................................................................................................................... 41
6.3 TRANSMIT ALL ONES (TAOS) .................................................................................................................... 42
Figure 34. Transmit All Ones (TAOS) .............................................................................................................
7.0 Microprocessor interface Block .....................................................................................................
TABLE 11: SELECTING THE MICROPROCESSOR INTERFACE MODE ......................................................................
Figure 35. Simplified Block Diagram of the Microprocessor Interface Block ..................................................
42
43
43
43
7.1 THE MICROPROCESSOR INTERFACE BLOCK SIGNALS ........................................................................................ 44
TABLE 12: XRT75R06 MICROPROCESSOR INTERFACE SIGNALS ........................................................................ 44
7.2 ASYNCHRONOUS AND SYNCHRONOUS DESCRIPTION ......................................................................................... 45
TABLE 13: ASYNCHRONOUS TIMING SPECIFICATIONS ......................................................................................... 46
Figure 37. Synchronous µP Interface Signals During Programmed I/O Read and Write Operations ............ 46
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Figure 36. Asynchronous µP Interface Signals During Programmed I/O Read and Write Operations ........... 46
TABLE 14: SYNCHRONOUS TIMING SPECIFICATIONS ........................................................................................... 47
Figure 38. Interrupt process ............................................................................................................................ 48
7.2.1 Hardware Reset: ................................................................................................................................. 49
TABLE 15: REGISTER MAP AND BIT NAMES ........................................................................................................
TABLE 16: REGISTER MAP DESCRIPTION - GLOBAL ............................................................................................
TABLE 17: REGISTER MAP AND BIT NAMES - CHANNEL N REGISTERS (N = 0,1,2,3,4,5) ......................................
TABLE 18: REGISTER MAP DESCRIPTION - CHANNEL N .......................................................................................
8.0 ELECTRICAL CHARACTERISTICS .................................................................................................
TABLE 19: ABSOLUTE MAXIMUM RATINGS ..........................................................................................................
TABLE 20: DC ELECTRICAL CHARACTERISTICS: .................................................................................................
49
50
50
52
57
57
57
APPENDIX - A .................................................................................................................. 58
TABLE 21: TRANSFORMER RECOMMENDATIONS ..................................................................................... 58
TABLE 22: TRANSFORMER DETAILS ................................................................................................................... 58
ORDERING INFORMATION ................................................................................................................. 59
PACKAGE DIMENSIONS - 23 X 23 MM 217 LEAD BGA PACKAGE .................................................................. 59
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PIN DESCRIPTIONS (BY FUNCTION)
TRANSMIT INTERFACE
LEAD #
SIGNAL NAME
TYPE
T15
R16
R15
N14
P14
P13
TxON_0
TxON_1
TxON_2
TxON_3
TxON_4
TxON_5
I
DESCRIPTION
Transmitter ON Input - Channel 0:
Transmitter ON Input - Channel 1:
Transmitter ON Input - Channel 2:
Transmitter ON Input - Channel 3:
Transmitter ON Input - Channel 4:
Transmitter ON Input - Channel 5:
These pins are active only when the corresponding TxON bits are set.
Table below shows the status of the transmitter based on theTxON bit and TxON
pin settings.
Bit
Pin
Transmitter Status
0
0
OFF
0
1
OFF
1
0
OFF
1
1
ON
NOTES:
1. These pins will be active and can control the TTIP and TRING outputs
only when the TxON_n bits in the channel register are set .
2. When Transmitters are turned off the TTIP and TRING outputs are Tristated.
3. These pins are internally pulled up.
E3
M3
F15
P16
G3
H15
TxCLK_0
TxCLK_1
TxCLK_2
TxCLK_3
TxCLK_4
TxCLK_5
I
Transmit Clock Input for TPOS and TNEG - Channel 0:
Transmit Clock Input for TPOS and TNEG - Channel 1:
Transmit Clock Input for TPOS and TNEG - Channel 2:
Transmit Clock Input for TPOS and TNEG - Channel 3:
Transmit Clock Input for TPOS and TNEG - Channel 4:
Transmit Clock Input for TPOS and TNEG - Channel 5:
The frequency accuracy of this input clock must be of nominal bit rate ± 20 ppm.
The duty cycle can be 30%-70%.
By default, input data is sampled on the falling edge of TxCLK.
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TRANSMIT INTERFACE
LEAD #
SIGNAL NAME
TYPE
F2
P2
G15
R17
H3
K15
TNEG_0
TNEG_1
TNEG_2
TNEG_3
TNEG_4
TNEG_5
I
DESCRIPTION
Transmit Negative Data Input - Channel 0:
Transmit Negative Data Input - Channel 1:
Transmit Negative Data Input - Channel 2:
Transmit Negative Data Input - Channel 3:
Transmit Negative Data Input - Channel 4:
Transmit Negative Data Input - Channel 5:
In Dual-rail mode, these pins are sampled on the falling or rising edge of TxCLK_n
.
NOTES:
1. These input pins are ignored and must be grounded if the Transmitter
Section is configured to accept Single-Rail data from the Terminal
Equipment.
F3
N3
F16
P15
G2
J15
TPOS_0
TPOS_1
TPOS_2
TPOS_3
TPOS_4
TPOS_5
I
Transmit Positive Data Input - Channel 0:
Transmit Positive Data Input - Channel 1:
Transmit Positive Data Input - Channel 2:
Transmit Positive Data Input - Channel 3:
Transmit Positive Data Input - Channel 4:
Transmit Positive Data Input - Channel 5:
By default sampled on the falling edge of TxCLK.
D1
N1
D17
N17
H1
H17
TTIP_0
TTIP_1
TTIP_2
TTIP_3
TTIP_4
TTIP_5
O
Transmit TTIP Output - Channel 0:
Transmit TTIP Output - Channel 1:
Transmit TTIP Output - Channel 2:
Transmit TTIP Output - Channel 3:
Transmit TTIP Output - Channel 4:
Transmit TTIP Output - Channel 5:
These pins along with TRING transmit bipolar signals to the line using a 1:1 transformer.
E1
M1
E17
M17
J1
J17
TRING_0
TRING_1
TRING_2
TRING_3
TRING_4
TRING_5
O
Transmit Ring Output - Channel 0:
Transmit Ring Output - Channel 1:
Transmit Ring Output - Channel 2:
Transmit Ring Output - Channel 3:
Transmit Ring Output - Channel 4:
Transmit Ring Output - Channel 5:
These pins along with TTIP transmit bipolar signals to the line using a 1:1 transformer.
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RECEIVE INTERFACE
LEAD #
SIGNAL NAME
TYPE
DESCRIPTION
A2
U2
A17
U17
D8
P8
RxCLK_0
RXCLK_1
RxCLK_2
RxCLK_3
RxCLK_4
RxCLK_5
O
Receive Clock Output - Channel 0:
Receive Clock Output - Channel 1:
Receive Clock Output - Channel 2:
Receive Clock Output - Channel 3:
Receive Clock Output - Channel 4:
Receive Clock Output - Channel 5:
By default, RPOS and RNEG data sampled on the rising edge RxCLK..
Set the RxCLKINV bit to sample RPOS/RNEG data on the falling edge of RxCLK
A1
U1
A16
U16
D9
P9
RPOS_0
RPOS_1
RPOS_2
RPOS_3
RPOS_4
RPOS_5
O
Receive Positive Data Output - Channel 0:
Receive Positive Data Output - Channel 1:
Receive Positive Data Output - Channel 2:
Receive Positive Data Output - Channel 3:
Receive Positive Data Output - Channel 4:
Receive Positive Data Output - Channel 5:
NOTE: If the B3ZS/HDB3 Decoder is enabled in Single-rail mode, then the zero
suppression patterns in the incoming line signal (such as: "00V", "000V",
"B0V", "B00V") are removed and replaced with ‘0’.
B2
T2
B16
T16
D10
P10
RNEG_0/
LCV_0
RNEG_1/
LCV_1
RNEG_2/
LCV_2
RNEG_3/
LCV_3
RNEG_4/
LCV_4
RNEG_5/
LCV_5
O
Receive Negative Data Output/Line Code Violation Indicator - Channel 0:
Receive Negative Data Output/Line Code Violation Indicator - Channel 1:
Receive Negative Data Output/Line Code Violation Indicator - Channel 2:
Receive Negative Data Output/Line Code Violation Indicator - Channel 3:
Receive Negative Data Output/Line Code Violation Indicator - Channel 4:
Receive Negative Data Output/Line Code Violation Indicator - Channel 5:
In Dual Rail mode, a negative pulse is output through RNEG.
Line Code Violation Indicator - Channel n:
If configured in Single Rail mode then Line Code Violation will be output.
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RECEIVE INTERFACE
LEAD #
SIGNAL NAME
TYPE
A5
U5
A14
U14
A9
U9
RRING_0
RRING_1
RRING_2
RRING_3
RRING_4
RRING_5
I
DESCRIPTION
Receive Input - Channel 0:
Receive Input - Channel 1:
Receive Input - Channel 2:
Receive Input - Channel 3:
Receive Input - Channel 4:
Receive Input - Channel 5:
These pins along with RTIP receive the bipolar line signal from the remote DS3/
E3/STS-1 Terminal.
A6
U6
A13
U13
A10
U10
RTIP_0
RTIP_1
RTIP_2
RTIP_3
RTIP_4
RTIP_5
I
Receive Input - Channel 0:
Receive Input - Channel 1:
Receive Input - Channel 2:
Receive Input - Channel 3:
Receive Input - Channel 4:
Receive Input - Channel 5:
These pins along with RRING receive the bipolar line signal from the Remote
DS3/E3/STS-1 Terminal.
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CLOCK INTERFACE
LEAD #
SIGNAL NAME
TYPE
E15
E3CLK
I
DESCRIPTION
E3 Clock Input (34.368 MHz ± 20 ppm):
If any of the channels is configured in E3 mode, a reference clock 34.368 MHz
is applied on this pin.
NOTE: In single frequency mode, this reference clock is not required.
G16
DS3CLK
I
DS3 Clock Input (44.736 MHz ± 20 ppm):
If any of the channels is configured in DS3 mode, a reference clock 44.736
MHz. is applied on this pin.
NOTE: In single frequency mode, this reference clock is not required.
C16
STS-1CLK/
12M
I
STS-1 Clock Input (51.84 MHz ± 20 ppm):
If any of the channels is configured in STS-1 mode, a reference clock 51.84
MHz is applied on this pin..
In Single Frequency Mode, a reference clock of 12.288 MHz ± 20 ppm is connected to this pin and the internal clock synthesizer generates the appropriate
clock frequencies based on the configuration of the channels in E3, DS3 or
STS-1 modes.
L15
SFM_EN
I
Single Frequency Mode Enable:
Tie this pin “High” to enable the Single Frequency Mode. A reference clock of
12.288 MHz ± 20 ppm is applied.
In the Single Frequency Mode (SFM) a low jitter output clock is provided for
each channel if the CLK_EN bit is set thus eliminating the need for a separate
clock source for the framer.
Tie this pin “Low” if single frequency mode is not selected. In this case, the
appropriate reference clocks must be provided.
NOTE:
B1
T1
B17
T17
D11
P11
CLKOUT_0
CLKOUT_1
CLKOUT_2
CLKOUT_3
CLKOUT_4
CLKOUT_5
O
This pin is internally pulled down
Clock output for channel 0
Clock output for channel 1
Clock output for channel 2
Clock output for channel 3
Clock output for channel 4
Clock output for channel 5
Low jitter clock output for each channel based on the mode selection (E3,DS3
or STS-1) if the CLKOUTEN_n bit is set in the control register.
This eliminates the need for a separate clock source for the framer.
NOTES:
1. The maximum drive capability for the clockouts is 16 mA.
2. This clock out is available both in SFM and non-SFM modes.
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CONTROL AND ALARM INTERFACE
LEAD #
B7
R6
C14
R14
C6
D14
SIGNAL NAME TYPE
MRING_0
MRING_1
MRING_2
MRING_3
MRING_4
MRING_5
I
DESCRIPTION
Monitor Ring Input - Channel 0:
Monitor Ring Input - Channel 1:
Monitor Ring Input - Channel 2:
Monitor Ring Input - Channel 3:
Monitor Ring Input - Channel 4:
Monitor Ring Input - Channel 5:
The bipolar line output signal from TRING_n is connected to this pin via a 270 Ω
resistor to check for line driver failure.
NOTE: This pin is internally pulled up.
B8
R7
C13
R13
C7
D13
MTIP_0
MTIP_1
MTIP_2
MTIP_3
MTIP_4
MTIP_5
I
Monitor Tip Input - Channel 0:
Monitor Tip Input - Channel 1:
Monitor Tip Input - Channel 2:
Monitor Tip Input - Channel 3:
Monitor Tip Input - Channel 4:
Monitor Tip Input - Channel 5:
The bipolar line output signal from TTIP_n is connected to this pin via a 270ohm resistor to check for line driver failure.
NOTE: This pin is internally pulled up.
C5
T4
B12
T12
D5
B15
DMO_0
DMO_1
DMO_2
DMO_3
DMO_4
DMO_5
O
Drive Monitor Output - Channel 0:
Drive Monitor Output - Channel 1:
Drive Monitor Output - Channel 2:
Drive Monitor Output - Channel 3:
Drive Monitor Output - Channel 4:
Drive Monitor Output - Channel 5:
If MTIP_n and MRING_n has no transition pulse for 128 ± 32 TxCLK_n cycles,
DMO_n goes “High” to indicate the driver failure. DMO_n output stays “High”
until the next AMI signal is detected.
C8
T7
C12
T11
B11
R8
RLOS_0
RLOS_1
RLOS_2
RLOS_3
RLOS_4
RLOS_5
O
Receive Loss of Signal - Channel 0:
Receive Loss of Signal - Channel 1:
Receive Loss of Signal - Channel 2:
Receive Loss of Signal - Channel 3:
Receive Loss of Signal - Channel 4:
Receive Loss of Signal - Channel 5:
This output pin toggles "High" if the receiver has detected a Loss of Signal Condition.
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CONTROL AND ALARM INTERFACE
C9
T8
D12
R11
C11
R9
RLOL_0
RLOL_1
RLOL_2
RLOL_3
RLOL_4
RLOL_5
O
Receive Loss of Lock - Channel 0:
Receive Loss of Lock - Channel 1:
Receive Loss of Lock - Channel 2:
Receive Loss of Lock - Channel 3:
Receive Loss of Lock - Channel 4:
Receive Loss of Lock - Channel 5:
This output pin toggles "High" if a Loss of Lock Condition is detected. LOL
(Loss of Lock) condition occurs if the recovered clock frequency deviates from
the Reference Clock frequency (available at either E3CLK or DS3CLK or STS1CLK input pins) by more than 0.5%.
L16
RXA
****
External Resistor of 3.01K Ω ± 1%.
Should be connected between RxA and RxB for internal bias.
K16
RXB
****
External Resistor of 3.01K Ω ±1%.
Should be connected between RxA and RxB for internal bias.
P12
ICT
I
In-Circuit Test Input:
Setting this pin "Low" causes all digital and analog outputs to go into a highimpedance state to allow for in-circuit testing. For normal operation, tie this pin
"High".
NOTE: This pin is internally pulled up.
R12
TEST
****
Factory Test Pin
NOTE: This pin must be connected to GND for normal operation.
MICROPROCESSOR INTERFACE
LEAD #
SIGNAL NAME
TYPE
K3
CS
I
Chip Select
Tie this “Low” to enable the communication with the Microprocessor Interface.
R1
PCLK
I
Processor Clock Input
To operate the Microprocessor Interface, appropriate clock frequency is provided through this pin. Maximum frequency is 66 Mhz.
K2
WR
I
Write Data :
To write data into the registers, this active low signal is asserted.
L2
RD
I
Read Data:
To read data from the registers, this active low pin is asserted.
J3
RESET
I
Register Reset:
DESCRIPTION
Setting this input pin "Low" resets the contents of the Command Registers to
their default settings and default operating configuration
NOTE: This pin is internally pulled up.
L3
PMODE
I
Processor Mode Select:
When this pin is tied “High”, the microprocessor is operating in synchronous
mode which means that clock must be applied to the PCLK (pin 55).
Tie this pin “Low” to select the Asynchronous mode. An internal clock is provided for the microprocessor interface.
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MICROPROCESSOR INTERFACE
LEAD #
SIGNAL NAME
TYPE
T3
RDY
O
DESCRIPTION
Ready Acknowledge:
NOTE: This pin must be connected to VDD via 3 kΩ ± 1% resistor.
U3
INT
O
INTERRUPT Output:
A transition to “Low” indicates that an interrupt has been generated. The interrupt function can be disabled by clearing the interrupt enable bit in the Channel
Control Register.
NOTES:
1.
This pin will remain asserted “Low” until the interrupt is serviced.
2. This pin must be conneced to VDD via 3 kΩ ± 1% resistor.
B4
A3
B3
C4
C3
C2
D3
D4
ADDR[0]
ADDR[1]
ADDR[2]
ADDR[3]
ADDR[4]
ADDR[5]
ADDR[6]
ADDR[7]
I
N4
P3
P4
P5
R5
R4
R3
R2
D[0]
D[1]
D[2]
D[3]
D[4]
D[5]
D[6]
D[7]
I/O
ADDRESS BUS:
8 bit address bus for the microprocessor interface
DATA BUS:
8 bit Data Bus for the microprocessor interface
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ANALOG POWER AND GROUND
LEAD #
SIGNAL NAME
TYPE
E2
TxAVDD_0
****
Transmitter Analog 3.3 V ± 5% VDD - Channel 0
N2
TxAVDD_1
****
Transmitter Analog 3.3 V ± 5% VDD - Channel 1
E16
TxAVDD_2
****
Transmitter Analog 3.3 V ± 5% VDD - Channel 2
N16
TxAVDD_3
****
Transmitter Analog 3.3 V ± 5% VDD - Channel 3
J2
TxAVDD_4
****
Transmitter Analog 3.3 V ± 5% VDD - Channel 4
J16
TxAVDD_5
****
Transmitter Analog 3.3 V ± 5% VDD - Channel 5
D2
TxAGND_0
****
Transmitter Analog GND - Channel 0
M2
TxAGND_1
****
Transmitter Analog GND - Channel 1
D16
TxAGND_2
****
Transmitter Analog GND - Channel 2
M16
TxAGND_3
****
Transmitter Analog GND - Channel 3
H2
TxAGND_4
****
Transmitter Analog GND - Channel 4
H16
TxAGND_5
****
Transmitter Analog GND - Channel 5
A4
RxAVDD_0
****
Receiver Analog 3.3 V ± 5% VDD - Channel 0
U4
RxAVDD_1
****
Receiver Analog 3.3 V ± 5% VDD - Channel 1
A15
RxAVDD_2
****
Receiver Analog 3.3 V ± 5% VDD - Channel 2
U15
RxAVDD_3
****
Receiver Analog 3.3 V ± 5% VDD - Channel 3
A8
RxAVDD_4
****
Receiver Analog 3.3 V ± 5% VDD - Channel 4
U8
RxAVDD_5
****
Receiver Analog 3.3 V ± 5% VDD - Channel 5
A7
RxAGND_0
****
Receiver Analog GND - Channel_0
U7
RxAGND_1
****
Receive Analog GND - Channel 1
A12
RxAGND_2
****
Receive Analog GND - Channel 2
U12
RxAGND_3
****
Receive Analog GND - Channel 3
A11
RxAGND_4
****
Receive Analog GND - Channel 4
U11
RxAGND_5
****
Receive Analog GND - Channel 5
E4
JaAVDD_0
****
Analog 3.3 V ± 5% VDD - Jitter Attenuator Channel 0
K4
JaAVDD_1
****
Analog 3.3 V ± 5% VDD - Jitter Attenuator Channel 1
E14
JaAVDD_2
****
Analog 3.3 V ± 5% VDD - Jitter Attenuator Channel 2
K14
JaAVDD_3
****
Analog 3.3 V ± 5% VDD - Jitter Attenuator Channel 3
G4
JaAVDD_4
****
Analog 3.3 V ± 5% VDD - Jitter Attenuator Channel 4
G14
JaAVDD_5
****
Analog 3.3 V ± 5% VDD - Jitter attenuator Channel 5
F4
JaAGND_0
****
Analog GND - Jitter Attenuator Channel 0
DESCRIPTION
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SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
ANALOG POWER AND GROUND
LEAD #
SIGNAL NAME
TYPE
J4
JaAGND_1
****
Analog GND - Jitter Attenuator Channel 1
F14
JaAGND_2
****
Analog GND - Jitter Attenuator Channel 2
J14
JaAGND_3
****
Analog GND - Jitter Attenuator Channel 3
H4
JaAGND_4
****
Analog GND - Jitter Attenuator Channel 4
H14
JaAGND_5
****
Analog GND - Jitter Attenuator Channel 5
C10
AGND
****
Analog GND
R10
AGND
****
Analog GND
H9
AGND
****
Analog GND
J9
AGND
****
Analog GND
K9
AGND
****
Analog GND
N15
REFAVDD
****
Analog 3.3 V ± 5% VDD - Reference
M15
REFGND
****
Reference GND
DESCRIPTION
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DIGITAL POWER AND GROUND
LEAD #
SIGNAL NAME
TYPE
F1
TxVDD_0
****
Transmitter 3.3 V ± 5% VDD Channel 0
L1
TxVDD_1
****
Transmitter 3.3 V ± 5% VDD Channel 1
F17
TxVDD_2
****
Transmitter 3.3 V ± 5% VDD Channel 2
L17
TxVDD_3
****
Transmitter 3.3 V ± 5% VDD Channel 3
K1
TxVDD_4
****
Transmitter 3.3 V ± 5% VDD Channel 4
K17
TxVDD_5
****
Transmitter 3.3 V ± 5% VDD Channel 5
C1
TxGND_0
****
Transmitter GND - Channel 0
P1
TxGND_1
****
Transmitter GND - Channel 1
C17
TxGND_2
****
Transmitter GND - Channel 2
P17
TxGND_3
****
Transmitter GND - Channel 3
G1
TxGND_4
****
Transmitter GND - Channel 4
G17
TxGND_5
****
Transmitter GND - Channel 5
B5
RxDVDD_0
****
Receiver 3.3 V ± 5% VDD - Channel 0
T5
RxDVDD_1
****
Receiver 3.3 V ± 5% VDD - Channel 1
B14
RxDVDD_2
****
Receiver 3.3 V ± 5% VDD - Channel 2
T14
RxDVDD_3
****
Receiver 3.3 V ± 5% VDD - Channel 3
B9
RxDVDD_4
****
Receiver 3.3 V ± 5% VDD - Channel 4
T9
RxDVDD_5
****
Receiver 3.3 V ± 5% VDD - Channel 5
B6
RxDGND_0
****
Receiver Digital GND - Channel 0
T6
RxDGND_1
****
Receiver Digital GND - Channel 1
B13
RxDGND_2
****
Receiver Digital GND - Channel 2
T13
RxDGND_3
****
Receiver Digital GND - Channel 3
B10
RxDGND_4
****
Receiver Digital GND - Channel 4
T10
RxDGND_5
****
Receiver Digital GND - Channel 5
P6
DVDD_1
****
VDD 3.3 V ± 5%
C15
DVDD_2
****
VDD 3.3 V ± 5%
L4
JaDVDD_1
****
VDD 3.3 V ± 5%
D6
DVDD(uP)
****
VDD 3.3 V ± 5%
L14
JaDVDD_2
****
VDD 3.3 V ± 5%
D15
DGND_1
****
Digital GND
D7
DGND(uP)
****
Digital GND
DESCRIPTION
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REV. 1.0.0
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
DIGITAL POWER AND GROUND
LEAD #
SIGNAL NAME
TYPE
M14
JaDGND_2
****
Digital GND
M4
JaDGND_1
****
Digital GND
P7
DGND
****
Digital GND
H8
DGND
****
Digital GND
J8
DGND
****
Digital GND
K8
DGND
****
Digital GND
H10
DGND
****
Digital GND
J10
DGND
****
Digital GND
K10
DGND
****
Digital GND
DESCRIPTION
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FUNCTIONAL DESCRIPTION
The XRT75R06 is a six channel fully integrated Line Interface Unit featuring EXAR’s R3 Technology
(Reconfigurable, Relayless Redundancy) for E3/DS3/STS-1 applications. The LIU incorporates 6 independent
Receivers, Transmitters and Jitter Attenuators in a single 217 Lead BGA package. Each channel can be
independently programmed to support E3, DS-3 or STS-1 line rates using one input clock reference of
12.288MHz in Single Frequency Mode (SFM). The LIU is responsible for providing the physical connection
between a line interface and an aggregate mapper or framing device. Along with the analog-to-digital
processing, the LIU offers monitoring and diagnostic features to help optimize network design implementation.
A key characteristic within the network topology is Automatic Protection Switching (APS).
EXAR’s proven expertise in providing redundany solutions has paved the way for R3 Technology.
1.0 R3 TECHNOLOGY (RECONFIGURABLE, RELAYLESS REDUNDANCY)
Redundancy is used to introduce reliability and protection into network card design. The redundant card in
many cases is an exact replicate of the primary card, such that when a failure occurs the network processor
can automatically switch to the backup card. EXAR’s R3 technology has re-defined E3/DS-3/STS-1 LIU design
for 1:1 and 1+1 redundancy applications. Without relays and one Bill of Materials, EXAR offers multi-port,
integrated LIU solutions to assist high density aggregate applications and framing requirements with reliability.
The following section can be used as a reference for implementing R3 Technology with EXAR’s world leading
line interface units.
1.1
Network Architecture
A common network design that supports 1:1 or 1+1 redundancy consists of N primary cards along with N
backup cards that connect into a mid-plane or back-plane architecture without transformers installed on the
network cards. In addition to the network cards, the design has a line interface card with one source of
transformers, connectors, and protection components that are common to both network cards. With this
design, the bill of materials is reduced to the fewest amount of components. See Figure 3. for a simplified
block diagram of a typical redundancy design.
FIGURE 3. NETWORK REDUNDANCY ARCHITECTURE
GND
37.5Ω
Rx
Framer/
Mapper
0.01µF
LIU
31.6Ω
Tx
31.6Ω
1:1
Line Interface Card
Primary Line Card
0.01µF
Rx
Framer/
Mapper
37.5Ω
1:1
0.01µF
0.01µF
LIU
31.6Ω
Tx
31.6Ω
Redundant Line Card
Back
Plane
or
Mid
Plane
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SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
2.0 CLOCK SYNTHESIZER
The LIU uses a flexible user interface for accepting clock references to generate the internal master clocks
used to drive the LIU. The reference clock used to supply the microprocessor timing is generated from the DS3 or SFM clock input. Therefore, if the chip is configured for STS-1 only or E3 only, then the DS-3 input pin
must be connected to the STS-1 pin or E3 pin respectively. In DS-3 mode or when SFM is used, the STS-1
and E3 input pins can be left unconnected. If SFM is enabled by pulling the SFM_EN pin "High", 12.288MHz is
the only clock reference necessary to generate DS-3, E3, or STS-1 line rates and the microprocessor timing.
A simplified block diagram of the clock synthesizer is shown in Figure 4
FIGURE 4. SIMPLIFIED BLOCK DIAGRAM OF THE INPUT CLOCK CIRCUITRY DRIVING THE MICROPROCESSOR
SFM_EN
STS-1Clk/12M
DS3Clk
E3Clk
CLKOUT_n
Clock Synthesizer
LOL_n
0
µProcessor
1
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.
FIGURE 5. CLOCK DISTRIBUTION CONGIFURED IN E3 MODE WITHOUT USING SFM
DS3Clk
E3Clk
Clock Synthesizer
µProcessor
NOTE: For one input clock reference, the single frequency mode should be used.
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LOL_n
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3.0 THE RECEIVER SECTION
The receiver is designed so that the LIU can recover clock and data from an attenuated line signal caused by
cable loss or flat loss according to industry specifications. Once data is recovered, it is processed and
presented at the receiver outputs according to the format chosen to interface with a Framer/Mapper or ASIC.
This section describes the detailed operation of various blocks within the receive path. A simplified block
diagram of the receive path is shown in Figure 6.
FIGURE 6. RECEIVE PATH BLOCK DIAGRAM
Peak Detector
RTIP_n
RRing_n
AGC/
Equalizer
Clock & Data
Recovery
Slicer
Jitter
Attenuator
HDB3/
B3ZS
Decoder
MUX
LOS
Detector
RxClk_n
RxPOS_n
RxNEG/LCV_n
RLOS_n
Channel n
3.1
Receive Line Interface
Physical Layer devices are AC coupled to a line interface through a 1:1 transformer. The transformer provides
isolation and a level shift by blocking the DC offset of the incoming data stream. The typical medium for the
line interface is a 75Ω coxial cable. Whether using E3, DS-3 or STS-1, the LIU requires the same bill of
materials, see Figure 7.
FIGURE 7. RECEIVE LINE INTERFACECONNECTION
1:1
RTIP_n
75Ω
Receiver
RRing_n
DS-3/E3/STS-1
37.5Ω
37.5Ω
0.01µF
RLOS_n
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3.2
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
Adaptive Gain Control (AGC)
The Adaptive Gain Control circuit amplifies the incoming analog signal and compensates for the various flat
losses and also for the loss at one-half symbol rate. The AGC has a dynamic range of 30 dB. The peak
detector provides feedback to the equalizer before slicing occurs.
3.3
Receive Equalizer
The Equalizer restores the integrity of the signal and compensates for the frequency dependent attenuation of
up to 900 feet of coaxial cable (1300 feet for E3). The Equalizer also boosts the high frequency content of the
signal to reduce Inter-Symbol Interference (ISI) so that the slicer slices the signal at 50% of peak voltage to
generate Positive and Negative data. The equalizer can be disabled by programming the appropriate register.
FIGURE 8. ACG/EQUALIZER BLOCK DIAGRAM
Peak Detector
RTIP_n
RRing_n
AGC/
Equalizer
Slicer
LOS
Detector
3.3.1
Recommendations for Equalizer Settings
The Equalizer has two gain settings to provide optimum equalization. In the case of normally shaped DS3/
STS-1 pulses (pulses that meet the template requirements) that has been driven through 0 to 900 feet of cable,
the Equalizer can be enabled. However, for square-shaped pulses such as E3 or for DS3/STS-1 high pulses
(that does not meet the pulse template requirements), it is recommended that the Equalizer be disabled for
cable length less than 300 feet. This would help to prevent over-equalization of the signal and thus optimize
the performance in terms of better jitter transfer characteristics. The Equalizer also contains an additional 20
dB gain stage to provide the line monitoring capability of the resistively attenuated signals which may have
20dB flat loss. The equalizer gain mode can be enabled by programming the appropriate register.
NOTE: The results of extensive testing indicate that even when the Equalizer was enabled, regardless of the cable length,
the integrity of the E3 signal was restored properly over 0 to 12 dB cable loss at Industrial Temperature.
3.4
Clock and Data Recovery
The Clock and Data Recovery Circuit extracts the embedded clock, RxClk_n from the sliced digital data stream
and provides the retimed data to the B3ZS (HDB3) decoder. The Clock Recovery PLL can be in one of the
following two modes:
3.4.1
Data/Clock Recovery Mode
In the presence of input line signals on the RTIP_n and RRing_n input pins and when the frequency difference
between the recovered clock signal and the reference clock signal is less than 0.5%, the clock that is output on
the RxClk_n out pins is the Recovered Clock signal.
3.4.2
Training Mode
In the absence of input signals at RTIP_n and RRing_n pins, or when the frequency difference between the
recovered line clock signal and the reference clock applied on the ExClk_n input pins exceed 0.5%, a Loss of
Lock condition is declared by toggling RLOL_n output pin “High” or setting the RLOL_n bit to “1” in the control
register. Also, the clock output on the RxClk_n pins are the same as the reference channel clock.
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SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
3.5
REV. 1.0.0
LOS (Loss of Signal) Detector
3.5.1
DS3/STS-1 LOS Condition
A Digital Loss of SIgnal (DLOS) condition occurs when a string of 175 ± 75 consecutive zeros occur on the line.
When the DLOS condition occurs, the DLOS_n bit is set to “1” in the status control register. DLOS condition is
cleared when the detected average pulse density is greater than 33% for 175 ± 75 pulses. Analog Loss of
Signal (ALOS) condition occurs when the amplitude of the incoming line signal is below the threshold as shown
in the Table 1.The status of the ALOS condition is reflected in the ALOS_n status control register. RLOS is the
logical OR of the DLOS and ALOS states. When the RLOS condition occurs the RLOS_n output pin is toggled
“High” and the RLOS_n bit is set to “1” in the status control register.
TABLE 1: THE ALOS (ANALOG LOS) DECLARATION AND CLEARANCE THRESHOLDS FOR A GIVEN SETTING OF
LOSTHR AND REQEN (DS3 AND STS-1 APPLICATIONS)
APPLICATION REQEN SETTING LOSTHR SETTING
DS3
STS-1
3.5.2
SIGNAL LEVEL TO DECLARE ALOS
DEFECT
SIGNAL LEVEL TO CLEAR ALOS
DEFECT
0
0
< 75mVpk
> 130mVpk
1
0
< 45mVpk
> 60mVpk
0
1
< 120mVpk
> 45mVpk
1
1
< 55mVpk
> 180mVpk
0
0
< 120mVpk
> 170mVpk
1
0
< 50mVpk
> 75mVpk
0
1
< 125mVpk
> 205mVpk
1
1
< 55mVpk
> 90mVpk
Disabling ALOS/DLOS Detection
For debugging purposes it is useful to disable the ALOS and/or DLOS detection. Writing a “1” to both
ALOSDIS_n and DLOSDIS_n bits disables the LOS detection on a per channel basis.
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3.5.3
E3 LOS Condition:
If the level of incoming line signal drops below the threshold as described in the ITU-T G.775 standard, the
LOS condition is detected. Loss of signal is defined as no transitions for 10 to 255 consecutive zeros. No
transitions is defined as a signal level between 15 and 35 dB below the normal. This is illustrated in Figure 9.
The LOS condition is cleared within 10 to 255 UI after restoration of the incoming line signal. Figure 10 shows
the LOS declaration and clearance conditions.
FIGURE 9. LOSS OF SIGNAL DEFINITION FOR E3 AS PER ITU-T G.775
0 dB
Maximum Cable Loss for E3
LOS Signal Must be Cleared
-12 dB
-15dB
LOS Signal may be Cleared or Declared
-35dB
LOS Signal Must be Declared
FIGURE 10. LOSS OF SIGNAL DEFINITION FOR E3 AS PER ITU-T G.775.
Actual Occurrence
of LOS Condition
Line Signal
is Restored
RTIP/
RRing
10 UI
255 UI
Time Range for
LOS Declaration
10 UI
255 UI
RLOS Output Pin
0 UI
0 UI
G.775
Compliance
Time Range for
LOS Clearance
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3.5.4
REV. 1.0.0
Interference Tolerance
For E3 mode, ITU-T G.703 Recommendation specifies that the receiver be able to recover error free clock and
data in the presence of a sinusoidal interfering tone signal. For DS3 and STS-1 modes, the same
recommendation is being used. Figure 11 shows the configuration to test the interference margin for DS3/
STS1. Figure 12 shows the set up for E3.
FIGURE 11. INTERFERENCE MARGIN TEST SET UP FOR DS3/STS-1
Attenuator
N
Sine Wave
Generator
DS3 = 22.368 MHz
STS-1 = 25.92 MHz
DUT
XRT75R06
∑
Test
Equipment
Cable Simulator
Pattern Generator
2 23 -1 PRBS
S
FIGURE 12. INTERFERENCE MARGIN TEST SET UP FOR E3.
Attenuator 1
Sine Wave
Generator
17.184mHz
Attenuator 2
N
∑
DUT
XRT75R06
Test
Equipment
Signal Source
223-1 PRBS
Cable Simulator
S
22
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
TABLE 2: INTERFERENCE MARGIN TEST RESULTS
MODE
CABLE LENGTH (ATTENUATION)
INTERFERENCE TOLERANCE
Equalizer “IN”
E3
DS3
STS-1
-17 dB
0 dB
12 dB
-14 dB
0 feet
-15 dB
225 feet
-15 dB
450 feet
-14 dB
0 feet
-15 dB
225 feet
-14 dB
450 feet
-14 dB
23
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
3.5.5
REV. 1.0.0
Muting the Recovered Data with LOS condition:
When the LOS condition is declared, the clock recovery circuit locks into the reference clock applied to the
internal master clock outputs this clock onto the RxClk_n output pin. The data on the RxPOS_n and RxNEG_n
pins can be forced to zero by setting the LOSMUT_n bits in the individual channel control register to “1”.
NOTE: When the LOS condition is cleared, the recovered data is output on RxPOS_n and RxNEG_n pins.
FIGURE 13. RECEIVER DATA OUTPUT AND CODE VIOLATION TIMING
tRRX
tFRX
RxClk
tLCVO
LCV
tCO
RPOS or
RNEG
SYMBOL
RxClk
PARAMETER
Duty Cycle
MIN
TYP
MAX
UNITS
45
50
55
%
RxClk Frequency
E3
34.368
MHz
DS-3
44.736
MHz
STS-1
51.84
MHz
tRRX
RxClk rise time (10% o 90%)
2
4
ns
tFRX
RxClk falling time (10% to 90%)
2
4
ns
tCO
RxClk to RPOS/RNEG delay time
4
ns
tLCVO
3.6
RxClk to rising edge of LCV output delay
2.5
ns
B3ZS/HDB3 Decoder
The decoder block takes the output from the clock and data recovery block and decodes the B3ZS (for DS3 or
STS-1) or HDB3 (for E3) encoded line signal and detects any coding errors or excessive zeros in the data
stream. Whenever the input signal violates the B3ZS or HDB3 coding sequence for bipolar violation or
contains three (for B3ZS) or four (for HDB3) or more consecutive zeros, an active “High” pulse is generated on
the RLCV_n output pins to indicate line code violation.
24
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XRT75R06
REV. 1.0.0
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
4.0 THE TRANSMITTER SECTION
The transmitter is designed so that the LIU can accept serial data from a local device, encode the data
properly, and then output an analog pulse according to the pulse shape chosen in the appropriate registers.
This section describes the detailed operation of various blocks within the transmit path. A simplified block
diagram of the transmit path is shown in Figure 14.
FIGURE 14. TRANSMIT PATH BLOCK DIAGRAM
TTIP_n
TRing_n
MTIP_n
MRing_n
Line
Driver
Device
Monitor
Tx
Pulse
Shaping
Jitter
Attenuator
Timing
Control
MUX
Tx
Control
TxClk_n
TxPOS_n
TxNEG_n
TxON
DMO_n
4.1
HDB3/
B3ZS
Encoder
Channel n
Transmit Digital Input Interface
The method for applying data to the transmit inputs of the LIU is a serial interface consisting of TxClk, TxPOS,
and TxNEG. For single rail mode, only TxClk and TxPOS are necessary for providing the local data from a
Framer device or ASIC. Data can be sampled on either edge of the input clock signal by programming the
appropriate register. A typical interface is shown in Figure 15.
FIGURE 15. TYPICAL INTERFACE BETWEEN TERMINAL EQUIPMENT AND THE XRT75R06 (DUAL-RAIL DATA)
Terminal
Equipment
(E3/DS3 or STS-1
Framer)
TxPOS
TPData
TxNEG
TNData
TxLineClk
TxClk
Transmit
Logic
Block
Exar E3/DS3/STS-1 LIU
25
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
FIGURE 16. TRANSMITTER TERMINAL INPUT TIMING
tRTX
tFTX
TxClk
tTSU
tTHO
TPData or
TNData
TTIP or
TRing
SYMBOL
TxClk
PARAMETER
Duty Cycle
MIN
TYP
MAX
UNITS
30
50
70
%
TxClk Frequency
E3
34.368
MHz
DS-3
44.736
MHz
STS-1
51.84
MHz
tRTX
TxClk Rise Time (10% to 90%)
4
ns
tFTX
TxClk Fall Time (10% to 90%)
4
ns
tTSU
TPData/TNData to TxClk falling set up time
3
ns
tTHO
TPData/TNData to TxClk falling hold time
3
ns
FIGURE 17. SINGLE-RAIL OR NRZ DATA FORMAT (ENCODER AND DECODER ARE ENABLED)
Data
1
1
TPData
TxClk
26
0
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SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
FIGURE 18. DUAL-RAIL DATA FORMAT (ENCODER AND DECODER ARE DISABLED)
Data
1
1
0
TPData
TNData
TxClk
4.2
Transmit Clock
The Transmit Clock applied via TxClk_n pins, for the selected data rate (for E3 = 34.368 MHz, DS3 = 44.736
MHz or STS-1 = 51.84 MHz), is duty cycle corrected by the internal PLL circuit to provide a 50% duty cycle
clock to the pulse shaping circuit. This allows a 30% to 70% duty cycle Transmit Clock to be supplied.
4.3
B3ZS/HDB3 ENCODER
When the Single-Rail (NRZ) data format is selected, the Encoder Block encodes the data into either B3ZS
format (for either DS3 or STS-1) or HDB3 format (for E3).
4.3.1
B3ZS Encoding
An example of B3ZS encoding is shown in Figure 19. If the encoder detects an occurrence of three
consecutive zeros in the data stream, it is replaced with either B0V or 00V, where ‘B’ refers to Bipolar pulse
that is compliant with the Alternating polarity requirement of the AMI (Alternate Mark Inversion) line code and
‘V’ refers to a Bipolar Violation (e.g., a bipolar pulse that violates the AMI line code). The substitution of B0V or
00V is made so that an odd number of bipolar pulses exist between any two consecutive violation (V) pulses.
This avoids the introduction of a DC component into the line signal.
FIGURE 19. B3ZS ENCODING FORMAT
TClk
4.3.2
TPDATA
1
0
Line
Signal
1
0
1 1
1
0
0
0
0
0
0
V
0
1
1
1
0
0
0
0
0
V
0
0
0
B
0
V
0
B
0
0
V
HDB3 Encoding
An example of the HDB3 encoding is shown in Figure 20. If the HDB3 encoder detects an occurrence of four
consecutive zeros in the data stream, then the four zeros are substituted with either 000V or B00V pattern. The
substitution code is made in such a way that an odd number of pulses exist between any consecutive V pulses.
This avoids the introduction of DC component into the analog signal.
27
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
FIGURE 20. HDB3 ENCODING FORMAT
TClk
4.4
TPDATA
1
0
Line
Signal
1
0
1 1
1
0
0
0
0
0
0
0
V
1
1
0
0
0
0
0
0
1
0
0
0
0
0
B
0
0
V
V
TRANSMIT PULSE SHAPER
The Transmit Pulse Shaper converts the B3ZS encoded digital pulses into a single analog Alternate Mark
Inversion (AMI) pulse that meets the industry standard mask template requirements for STS-1 and DS3. For
E3 mode, the pulse shaper converts the HDB3 encoded pulses into a single full amplitude square shaped
pulse with very little slope. The Pulse Shaper Block also includes a Transmit Build Out Circuit, which can
either be disabled or enabled by setting the TxLEV_n bit to “1” or “0” in the control register. For DS3/STS-1
rates, the Transmit Build Out Circuit is used to shape the transmit waveform that ensures that transmit pulse
template requirements are met at the Cross-Connect system. The distance between the transmitter output and
the Cross-Connect system can be between 0 to 450 feet. For E3 rate, since the output pulse template is
measured at the secondary of the transformer and since there is no Cross-Connect system pulse template
requirements, the Transmit Build Out Circuit is always disabled. The differential line driver increases the
transmit waveform to appropriate level and drives into the 75Ω load as shown in Figure 21.
FIGURE 21. TRANSMIT PULSE SHAPE TEST CIRCUIT
R1
TxPOS(n)
TxNEG(n)
TxLineClk(n)
TTIP(n)
TPData(n)
TNData(n)
TxClk(n)
TRing(n)
31.6Ω +1%
R2
31.6Ω + 1%
4.4.1
R3
75Ω
1:1
Guidelines for using Transmit Build Out Circuit
If the distance between the transmitter and the DSX3 or STSX-1, Cross-Connect system, is less than 225 feet,
enable the Transmit Build Out Circuit by setting the TxLEV_n control bit to “0”. If the distance between the
transmitter and the DSX3 or STSX-1 is greater than 225 feet, disable the Transmit Build Out Circuit.
28
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
4.5
E3 line side parameters
The XRT75R06 line output at the transformer output meets the pulse shape specified in ITU-T G.703 for
34.368 Mbits/s operation. The pulse mask as specified in ITU-T G.703 for 34.368 Mbits/s is shown in Figure
22.
FIGURE 22. PULSE MASK FOR E3 (34.368 MBITS/S) INTERFACE AS PER ITU-T G.703
17 ns
(14.55 + 2.45)
8.65 ns
V = 100%
Nominal Pulse
50%
14.55ns
12.1ns
(14.55 - 2.45)
10%
0%
10%
20%
29
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
TABLE 3: E3 TRANSMITTER LINE SIDE OUTPUT AND RECEIVER LINE SIDE INPUT SPECIFICATIONS
PARAMETER
MIN
TYP
MAX
UNITS
0.90
1.00
1.10
Vpk
Transmit Output Pulse Amplitude Ratio
0.95
1.00
1.05
Transmit Output Pulse Width
12.5
14.55
16.5
ns
0.02
0.05
UIPP
TRANSMITTER LINE SIDE OUTPUT CHARACTERISTICS
Transmit Output Pulse Amplitude
(Measured at secondary of the transformer)
Transmit Intrinsic Jitter
RECEIVER LINE SIDE INPUT CHARACTERISTICS
Receiver Sensitivity (length of cable)
900
1200
feet
Interference Margin
-20
-14
dB
Jitter Tolerance @ Jitter Frequency 800KHz
0.15
0.28
UI PP
Signal level to Declare Loss of Signal
-35
dB
Signal Level to Clear Loss of Signal
-15
Occurence of LOS to LOS Declaration Time
10
255
UI
Termination of LOS to LOS Clearance Time
10
255
UI
NOTE: The above values are at TA = 250C and VDD = 3.3 V± 5%.
30
dB
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
FIGURE 23. BELLCORE GR-253 CORE TRANSMIT OUTPUT PULSE TEMPLATE FOR SONET STS-1 APPLICATIONS
S T S -1 P u ls e T em p la te
1.2
1
0.6
Lower Curve
Upper Curve
0.4
0.2
0
2
3
4
1.
9
1.
8
0.
1.
7
0.
1
6
0.
1
5
0.
1.
4
0.
1
-0
.
3
2
-0
.
0.
3
-0
.
2
4
-0
.
0.
5
-0
.
0.
6
-0
.
0
7
-0
.
1
8
-0
.
0.
9
-0
.
-0.2
-1
Norm a lize d Am plitude
0.8
Tim e , in UI
TABLE 4: STS-1 PULSE MASK EQUATIONS
TIME IN UNIT INTERVALS
NORMALIZED AMPLITUDE
LOWER CURVE
- 0.03
-0.85 < T < -0.38
-0.38
·
π
T - – 0.03
0.5 1 + sin --- 1 + ---------
0.18
2
< T < 0.36
- 0.03
0.36 < T < 1.4
UPPER CURVE
-0.85 < T < -0.68
0.03
-0.68 < T < 0.26
·
π
T - + 0.03
0.5 1 + sin --- 1 + ---------
0.34
2
0.26 < T < 1.4
0.1 + 0.61 x e-2.4[T-0.26]
31
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
TABLE 5: STS-1 TRANSMITTER LINE SIDE OUTPUT AND RECEIVER LINE SIDE INPUT SPECIFICATIONS (GR-253)
PARAMETER
MIN
TYP
MAX
UNITS
0.65
0.75
0.90
Vpk
0.90
1.00
1.10
Vpk
Transmit Output Pulse Width
8.6
9.65
10.6
ns
Transmit Output Pulse Amplitude Ratio
0.90
1.00
1.10
0.02
0.05
TRANSMITTER LINE SIDE OUTPUT CHARACTERISTICS
Transmit Output Pulse Amplitude
(measured with TxLEV = 0)
Transmit Output Pulse Amplitude
(measured with TxLEV = 1)
Transmit Intrinsic Jitter
UIpp
RECEIVER LINE SIDE INPUT CHARACTERISTICS
Receiver Sensitivity (length of cable)
900
Jitter Tolerance @ Jitter Frequency 400 KHz
0.15
1100
feet
UIpp
Signal Level to Declare Loss of Signal
Refer to Table 10
Signal Level to Clear Loss of Signal
Refer to Table 10
NOTE: The above values are at TA = 250C and VDD = 3.3 V ± 5%.
FIGURE 24. TRANSMIT OUPUT PULSE TEMPLATE FOR DS3 AS PER BELLCORE GR-499
D S 3 P u ls e T e m p la te
1.2
1
0.6
Lower Curve
Upper Curve
0.4
0.2
0
3
4
9
0.
1.
8
0.
2
7
0.
1.
6
0.
1.
5
0.
1
4
0.
32
1
3
0.
T im e , in UI
1.
2
0.
0
1
0.
.2
.3
.4
.5
.6
.7
.8
.1
-0
-0
-0
-0
-0
-0
-0
-0
-1
.9
-0.2
-0
No rm a li z e d Am p litu d e
0.8
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
TABLE 6: DS3 PULSE MASK EQUATIONS
TIME IN UNIT INTERVALS
NORMALIZED AMPLITUDE
LOWER CURVE
- 0.03
-0.85 < T < -0.36
-0.36
·
π
T - – 0.03
0.5 1 + sin --- 1 + ---------
2
0.18
< T < 0.36
- 0.03
0.36 < T < 1.4
UPPER CURVE
-0.85 < T < -0.68
0.03
-0.68 < T < 0.36
·
π
T - + 0.03
0.5 1 + sin --- 1 + ---------
0.34
2
0.36 < T < 1.4
0.08 + 0.407 x e-1.84[T-0.36]
TABLE 7: DS3 TRANSMITTER LINE SIDE OUTPUT AND RECEIVER LINE SIDE INPUT SPECIFICATIONS (GR-499)
PARAMETER
MIN
TYP
MAX
UNITS
0.65
0.75
0.85
Vpk
0.90
1.00
1.10
Vpk
Transmit Output Pulse Width
10.10
11.18
12.28
ns
Transmit Output Pulse Amplitude Ratio
0.90
1.00
1.10
0.02
0.05
TRANSMITTER LINE SIDE OUTPUT CHARACTERISTICS
Transmit Output Pulse Amplitude
(measured with TxLEV = 0)
Transmit Output Pulse Amplitude
(measured with TxLEV = 1)
Transmit Intrinsic Jitter
UIpp
RECEIVER LINE SIDE INPUT CHARACTERISTICS
Receiver Sensitivity (length of cable)
900
Jitter Tolerance @ 400 KHz (Cat II)
0.15
1100
UIpp
Signal Level to Declare Loss of Signal
Refer to Table 10
Signal Level to Clear Loss of Signal
Refer to Table 10
NOTE: The above values are at TA = 250C and VDD = 3.3V ± 5%.
33
feet
áç
XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
4.6
REV. 1.0.0
Transmit Drive Monitor
This feature is used for monitoring the transmit line for occurrence of fault conditions such as a short circuit on
the line or a defective line driver. To activate this function, connect MTIP_n pins to the TTIP_n lines via a 270Ω
resistor and MRing_n pins to TRing_n lines via 270Ω resistor as shown in Figure 25.
FIGURE 25. TRANSMIT DRIVER MONITOR SET-UP.
R1
TTIP(n)
31.6Ω +1%
R3
75Ω
R2
TxPOS(n)
TxNEG(n)
TxLineClk(n)
TRing(n)
TPData(n)
TNData(n)
TxClk(n)
31.6Ω + 1%
1:1
R1
MTIP(n)
270Ω
R2
MRing(n)
270Ω
When the MTIP_n and MRing_n are connected to the TTIP_n and TRing_n lines, the drive monitor circuit
monitors the line for transitions. The DMO_n (Drive Monitor Output) will be asserted “Low” as long as the
transitions on the line are detected via MTIP_n and MRing_n. If no transitions on the line are detected for 128
± 32 TxClk_n periods, the DMO_n output toggles “High” and when the transitions are detected again, DMO_n
toggles “Low”.
NOTE: The Drive Monitor Circuit is only for diagnostic purpose and does not have to be used to operate the transmitter.
4.7
Transmitter Section On/Off
The transmitter section of each channel can either be turned on or off. To turn on the transmitter, set the input
pin TxON to “High” and write a “1” to the TxON_n control bit. When the transmitter is turned off, TTIP_n and
TRing_n are tri-stated.
NOTES:
1.
This feature provides support for Redundancy.
2. To permit a system designed for redundancy to quickly shut-off the defective line card and turn on the back-up line
card, writing a “1” to the TxON_n control bits transfers the control to TxON pin.
34
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SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
5.0 JITTER
There are three fundamental parameters that describe circuit performance relative to jitter
• Jitter Tolerance
• Jitter Transfer
• Jitter Generation
5.1
JITTER TOLERANCE
Jitter tolerance is a measure of how well a Clock and Data Recovery unit can successfully recover data in the
presence of various forms of jitter. It is characterized by the amount of jitter required to produce a specified bit
error rate. The tolerance depends on the frequency content of the jitter. Jitter Tolerance is measured as the
jitter amplitude over a jitter spectrum for which the clock and data recovery unit achieves a specified bit error
rate (BER). To measure the jitter tolerance as shown in Figure 26, jitter is introduced by the sinusoidal
modulation of the serial data bit sequence. Input jitter tolerance requirements are specified in terms of
compliance with jitter mask which is represented as a combination of points. Each point corresponds to a
minimum amplitude of sinusoidal jitter at a given jitter frequency.
FIGURE 26. JITTER TOLERANCE MEASUREMENTS
Pattern
Generator
Data
Error
Detector
DUT
XRT75R06
Clock
Modulation
Freq.
FREQ
Synthesizer
5.1.1
DS3/STS-1 Jitter Tolerance Requirements
Bellcore GR-499 CORE specifies the minimum requirement of jitter tolerance for Category I and Category II.
The jitter tolerance requirement for Category II is the most stringent. Figure 27 shows the jitter tolerance curve
as per GR-499 specification.
35
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
JITTER AMPLITUDE (UI
)
pp
FIGURE 27. INPUT JITTER TOLERANCE FOR DS3/STS-1
64
GR-253 STS-1
41
15
GR-499 Cat II
GR-499 Cat I
10
XRT75R06
5
1.5
0.3
0.15
0.1
0.01
0.03
0.3
2
20
100
JITTER FREQUENCY (kHz)
5.1.2
E3 Jitter Tolerance Requirements
ITU-T G.823 standard specifies that the clock and data recovery unit must be able to tolerate jitter up to certain
specified limits. Figure 28 shows the tolerance curve.
FIGURE 28. INPUT JITTER TOLERANCE FOR E3
ITU-T G.823
JITTER AMPLITUDE (UI
)
pp
64
XRT75R06
10
1.5
0.3
0.1
1
10
800
JITTER FREQUENCY (kHz)
As shown in the Figures above, in the jitter tolerance measurement, the dark line indicates the minimum level
of jitter that the E3/DS3/STS-1 compliant component must tolerate. Table 8 below shows the jitter amplitude
versus the modulation frequency for various standards.
36
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
TABLE 8: JITTER AMPLITUDE VERSUS MODULATION FREQUENCY (JITTER TOLERANCE)
INPUT JITTER AMPLITUDE (UI P-P)
BIT RATE
(KB/S)
STANDARD
34368
MODULATION FREQUENCY
A1
A2
A3
F1(HZ)
F2(HZ)
F3(KHZ)
F4(KHZ)
F5(KHZ)
ITU-T G.823
1.5
0.15
-
100
1000
10
800
-
44736
GR-499
CORE Cat I
5
0.1
-
10
2.3k
60
300
-
44736
GR-499
CORE Cat II
10
0.3
-
10
669
22.3
300
-
51840
GR-253
CORE Cat II
15
1.5
0.15
10
30
300
2
20
5.2
JITTER TRANSFER
Jitter Transfer function is defined as the ratio of jitter on the output relative to the jitter applied on the input
versus frequency. There are two distinct characteristics in jitter transfer, jitter gain (jitter peaking) defined as
the highest ratio above 0dB and jitter transfer bandwidth. The overall jitter transfer bandwidth is controlled by a
low bandwidth loop, typically using a voltage-controlled crystal oscillator (VCXO).
The jitter transfer function is a ratio between the jitter output and jitter input for a component, or system often
expressed in dB. A negative dB jitter transfer indicates the element removed jitter. A positive dB jitter transfer
indicates the element added jitter. A zero dB jitter transfer indicates the element had no effect on jitter. Table 9
shows the jitter transfer characteristics and/or jitter attenuation specifications for various data rates:
TABLE 9: JITTER TRANSFER SPECIFICATION/REFERENCES
E3
DS3
STS-1
ETSI TBR-24
GR-499 CORE section 7.3.2
Category I and Category II
GR-253 CORE section 5.6.2.1
NOTE: The above specifications can be met only with a jitter attenuator that supports E3/DS3/STS-1 rates.
5.3
Jitter Attenuator
An advanced crystal-less jitter attenuator per channel is included in the XRT75R06. The jitter attenuator
requires no external crystal nor high-frequency reference clock. By clearing or setting the JATx/Rx_n bits in
the channel control registers selects the jitter attenuator either in the Receive or Transmit path on per channel
basis. The FIFO size can be either 16-bit or 32-bit. The bits JA0_n and JA1_n can be set to appropriate
combination to select the different FIFO sizes or to disable the Jitter Attenuator on a per channel basis. Data is
clocked into the FIFO with the associated clock signal (TxClk or RxClk) and clocked out of the FIFO with the
dejittered clock. When the FIFO is within two bits of overflowing or underflowing, the FIFO limit status bit, FL_n
is set to “1” in the Alarm status register. Reading this bit clears the FIFO and resets the bit into default state.
NOTE: It is recommended to select the 16-bit FIFO for delay-sensitive applications as well as for removing smaller amounts
of jitter. Table 10 specifies the jitter transfer mask requirements for various data rates:
37
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XRT75R06
SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.0
TABLE 10: JITTER TRANSFER PASS MASKS
F1
(HZ)
F2
(HZ)
F3
(HZ)
F4
(KHZ)
A1(dB)
A2(dB)
G.823
ETSI-TBR-24
100
300
3K
800K
0.5
-19.5
44736
GR-499, Cat I
GR-499, Cat II
GR-253 CORE
10
10
10
10k
56.6k
40
-
15k
300k
15k
0.1
0.1
0.1
-
51840
GR-253 CORE
10
40k
-
400k
0.1
-
RATE
(KBITS)
MASK
34368
The jitter attenuator within the XRT75R06 meets the latest jitter attenuation specifications and/or jitter transfer
characteristics as shown in the Figure 29.
J IT T E R A M P L IT U D E
FIGURE 29. JITTER TRANSFER REQUIREMENTS AND JITTER ATTENUATOR PERFORMANCE
A1
A2
F1
F2
F3
F4
J IT T E R F R E Q U E N C Y ( k H z )
5.3.1
JITTER GENERATION
Jitter Generation is defined as the process whereby jitter appears at the output port of the digital equipment in
the absence of applied input jitter. Jitter Generation is measured by sending jitter free data to the clock and
data recovery circuit and measuring the amount of jitter on the output clock or the re-timed data. Since this is
essentially a noise measurement, it requires a definition of bandwidth to be meaningful. The bandwidth is set
according to the data rate. In general, the jitter is measured over a band of frequencies.
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6.0 DIAGNOSTIC FEATURES
6.1
PRBS Generator and Detector
The XRT75R06 contains an on-chip Pseudo Random Binary Sequence (PRBS) generator and detector for
diagnostic purpose. With the PRBSEN_n bit = “1”, the transmitter will send out PRBS of 223-1 in E3 rate or
215-1 in STS-1/DS3 rate. At the same time, the receiver PRBS detector is also enabled. When the correct
PRBS pattern is detected by the receiver, the RNEG/LCV pin will go “Low” to indicate PRBS synchronization
has been achieved. When the PRBS detector is not in sync the PRBSLS bit will be set to “1” and RNEG/LCV
pin will go “High”.
With the PRBS mode enabled, the user can also insert a single bit error by toggling “INSPRBS” bit. This is
done by writing a “1” to INSPRBS bit. The receiver at RNEG/LCV pin will pulse “High” for one RxClk cycle for
every bit error detected. Any subsequent single bit error insertion must be done by first writing a “0” to
INSPRBS bit and followed by a “1”.
Figure 30 shows the status of RNEG/LCV pin when the XRT75R06 is configured in PRBS mode.
NOTE: In PRBS mode, the device is forced to operate in Single-Rail Mode.
FIGURE 30. PRBS MODE
RxClk
SYNC LOSS
RxNEG/LCV
PRBS SYNC
Single Bit Error
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6.2
REV. 1.0.0
LOOPBACKS
The XRT75R06 offers three loopback modes for diagnostic purposes. The loopback modes are selected via
the RLB_n and LLB_n bits n the Channel control registers select the loopback modes.
6.2.1
ANALOG LOOPBACK
In this mode, the transmitter outputs TTIP_n and TRing_n are internally connected to the receiver inputs
RTIP_n and RRing_n as shown in Figure 31. Data and clock are output at RxClk_n, RxPOS_n and RxNEG_n
pins for the corresponding transceiver. Analog loopback exercises most of the functional blocks of the device
including the jitter attenuator which can be selected in either the transmit or receive path.
NOTES:
1. In the Analog loopback mode, data is also output via TTIP_n and TRing_n pins.
2. Signals on the RTIP_n and RRing_n pins are ignored during analog loopback.
HDB3/B3ZS
ENCODER
TxNEG
RxClk
RxPOS
RxNEG
HDB3/B3ZS
DECODER
JITTER
ATTENUATOR
TxClk
TxPOS
TIMING
CONTROL
JITTER
ATTENUATOR
FIGURE 31. ANALOG LOOPBACK
DATA &
CLOCK
RECOVERY
40
TTIP
Tx
TRing
RTIP
Rx
RRing
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6.2.2
DIGITAL LOOPBACK
When the Digital Loopback is selected, the transmit clock TxClk_n and transmit data inputs (TxPOS_n &
TxNEG_n are looped back and output onto the RxClk_n, RxPOS_n and RxNEG_n pins as shown in Figure 32.
HDB3/B3ZS
ENCODER
TxNEG
RxCLK
RxPOS
HDB3/B3ZS
DECODER
RxNEG
6.2.3
TIMING
CONTROL
JITTER
ATTENUATOR
TxCLK
TxPOS
JITTER
ATTENUATOR
FIGURE 32. DIGITAL LOOPBACK
DATA &
CLOCK
RECOVERY
TTIP
Tx
TRing
RTIP
Rx
RRing
REMOTE LOOPBACK
With Remote loopback activated as shown in Figure 33, the receive data on RTIP and RRing is looped back
after the jitter attenuator (if selected in receive or transmit path) to the transmit path using RxClk as transmit
timing. The receive data is also output via the RxPOS and RxNEG pins.
NOTE: Input signals on TxClk, TxPOS and TxNEG are ignored during Remote loopback.
HDB3/B3ZS
ENCODER
TxNEG
RxCLK
RxPOS
RxNEG
HDB3/B3ZS
DECODER
JITTER
ATTENUATOR
TxCLK
TxPOS
TIMING
CONTROL
JITTER
ATTENUATOR
FIGURE 33. REMOTE LOOPBACK
DATA &
CLOCK
RECOVERY
TTIP
Tx
TRing
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Rx
RRing
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6.3
REV. 1.0.0
TRANSMIT ALL ONES (TAOS)
Transmit All Ones (TAOS) can be set by setting the TAOS_n control bits to “1” in the Channel control registers.
When the TAOS is set, the Transmit Section generates and transmits a continuous AMI all “1’s” pattern on
TTIP_n and TRing_n pins. The frequency of this ones pattern is determined by TxClk_n. the TAOS data path
is shown in Figure 34. TAOS does not operate in Analog loopback or Remote loopback modes, however will
function in Digital loopback mode.
TxCLK
TxPOS
HDB3/B3ZS
ENCODER
TxNEG
JITTER
ATTENUATOR
FIGURE 34. TRANSMIT ALL ONES (TAOS)
TIMING
CONTROL
Tx
TTIP
Transmit All 1's
TRing
RxCLK
RxPOS
RxNEG
HDB3/B3ZS
DECODER
JITTER
ATTENUATOR
TAOS
DATA &
CLOCK
RECOVERY
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Rx
RRing
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7.0 MICROPROCESSOR INTERFACE BLOCK
The Microprocessor Interface section supports communication between the local microprocessor (µP) and the
LIU. The XRT75R06 supports a parallel interface asynchronously or synchronously timed to the LIU. The microprocessor interface is selected by the state of the Pmode input pin. Selecting the microprocessor interface
mode is shown in Table 11.
TABLE 11: SELECTING THE MICROPROCESSOR INTERFACE MODE
PMODE
MICROPROCESSOR MODE
"Low"
Asynchronous Mode
"High"
Synchronous Mode
The local µP configures the LIU by writing data into specific addressable, on-chip Read/Write registers. The
µP provides the signals which are required for a general purpose microprocessor to read or write data into
these registers. The µP also supports polled and interrupt driven environments. A simplified block diagram of
the microprocessor is shown in Figure 35.
FIGURE 35. SIMPLIFIED BLOCK DIAGRAM OF THE MICROPROCESSOR INTERFACE BLOCK
CS
WR
RD
Addr[7:0]
D[7:0]
PCLK
Microprocessor
Interface
Pmode
RESET
RDY
INT
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7.1 THE MICROPROCESSOR INTERFACE BLOCK SIGNALS
The LIU may be configured into different operating modes and have its performance monitored by software
through a standard microprocessor using data, address and control signals. These interface signals are described below in Table 12. The microprocessor interface can be configured to operate in Asynchronous mode
or Synchronous mode.
TABLE 12: XRT75R06 MICROPROCESSOR INTERFACE SIGNALS
PIN NAME
TYPE
DESCRIPTION
Pmode
I
D[7:0]
I/O
Addr[7:0]
I
Eight-Bit Address Bus Inputs
The XRT75R06 LIU microprocessor interface uses a direct address bus. This address bus is
provided to permit the user to select an on-chip register for Read/Write access.
CS
I
Chip Select Input
This active low signal selects the microprocessor interface of the XRT75R06 LIU and enables
Read/Write operations with the on-chip register locations.
RD
I
Read Signal This active low input functions as the read signal from the local µP. When this
pin is pulled “Low” (if CS is “Low”) the LIU is informed that a read operation has been
requested and begins the process of the read cycle.
WR
I
Write Signal This active low input functions as the write signal from the local µP. When this
pin is pulled “Low” (if CS is “Low”) the LIU is informed that a write operation has been
requested and begins the process of the write cycle.
RDY
O
Ready Output This active low signal is provided by the LIU device. It indicates that the current
read or write cycle is complete, and the LIU is waiting for the next command.
INT
O
Interrupt Output This active low signal is provided by the LIU to alert the local mP that a
change in alarm status has occured. This pin is Reset Upon Read (RUR) once the alarm status registers have been cleared.
RESET
I
Reset Input This active low input pin is used to Reset the LIU.
Microprocessor Interface Mode Select Input pin
This pin is used to specify the microprocessor interface mode.
Bi-Directional Data Bus for register "Read" or "Write" Operations.
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7.2 ASYNCHRONOUS AND SYNCHRONOUS DESCRIPTION
Whether the LIU is configured for Asynchronous or Synchronous mode, the following descriptions apply. The
synchronous mode requires an input clock (PCLK) to be used as the microprocessor timing reference. Read
and Write operations are described below.
Read Cycle (For Pmode = "0" or "1")
Whenever the local µP wishes to read the contents of a register, it should do the following.
1. Place the address of the target register on the address bus input pins Addr[7:0].
2. While the µP is placing this address value on the address bus, the address decoding circuitry should
assert the CS pin of the LIU, by toggling it "Low". This action enables communication between the µP and
the LIU microprocessor interface block.
3. Next, the µP should indicate that this current bus cycle is a Read operation by toggling the RD input pin
"Low". This action enables the bi-directional data bus output drivers of the LIU.
4. After the µP toggles the Read signal "Low", the LIU will toggle the RDY output pin "Low". The LIU does this
to inform the µP that the data is available to be read by the µP, and that it is ready for the next command.
5. After the µP detects the RDY signal and has read the data, it can terminate the Read Cycle by toggling the
RD input pin "High".
6. The CS input pin must be pulled "High" before a new command can be issued.
Write Cycle (For Pmode = "0" or "1")
Whenever a local µP wishes to write a byte or word of data into a register within the LIU, it should do the following.
1. Place the address of the target register on the address bus input pins Addr[7:0].
2. While the µP is placing this address value on the address bus, the address decoding circuitry should
assert the CS pin of the LIU, by toggling it "Low". This action enables communication between the µP and
the LIU microprocessor interface block.
3. The µP should then place the byte or word that it intends to write into the target register, on the bi-directional data bus D[7:0].
4. Next, the µP should indicate that this current bus cycle is a Write operation by toggling the WR input pin
"Low". This action enables the bi-directional data bus input drivers of the LIU.
5. After the µP toggles the Write signal "Low", the LIU will toggle the RDY output pin "Low". The LIU does this
to inform the µP that the data has been written into the internal register location, and that it is ready for the
next command.
6. The CS input pin must be pulled "High" before a new command can be issued.
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FIGURE 36. ASYNCHRONOUS µP INTERFACE SIGNALS DURING PROGRAMMED I/O READ AND WRITE OPERATIONS
READ OPERATION
WRITE OPERATION
t0
t0
Addr[7:0]
Valid Address
Valid Address
CS
D[7:0]
Valid Data for Readback
Data Available to Write Into the LIU
t1
RD
t3
WR
t2
t4
RDY
TABLE 13: ASYNCHRONOUS TIMING SPECIFICATIONS
SYMBOL
PARAMETER
MIN
MAX
UNITS
t0
Valid Address to CS Falling Edge
0
-
ns
t1
CS Falling Edge to RD Assert
0
-
ns
t2
RD Assert to RDY Assert
-
65
ns
RD Pulse Width (t2)
70
-
ns
t3
CS Falling Edge to WR Assert
0
-
ns
t4
WR Assert to RDY Assert
-
65
ns
70
-
ns
NA
NA
WR Pulse Width (t4)
FIGURE 37. SYNCHRONOUS µP INTERFACE SIGNALS DURING PROGRAMMED I/O READ AND WRITE OPERATIONS
READ OPERATION
WRITE OPERATION
PCLK
t0
t0
Addr[7:0]
Valid Address
Valid Address
CS
D[7:0]
Valid Data for Readback
Data Available to Write Into the LIU
t1
RD
t3
WR
t2
t4
RDY
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TABLE 14: SYNCHRONOUS TIMING SPECIFICATIONS
SYMBOL
PARAMETER
MIN
MAX
UNITS
t0
Valid Address to CS Falling Edge
0
-
ns
t1
CS Falling Edge to RD Assert
0
-
ns
t2
RD Assert to RDY Assert
-
35
RD Pulse Width (t2)
40
-
ns
t3
CS Falling Edge to WR Assert
0
-
ns
t4
WR Assert to RDY Assert
-
35
WR Pulse Width (t4)
40
-
PCLK Period
15
NA
NA
ns, see note 1
ns, see note 1
ns
ns
PCLK Duty Cycle
PCLK "High/Low" time
NOTE: 1. This timing parameter is based on the frequency of the synchronous clock (PCLK). To determine the access
time, use the following formula: (PCLKperiod * 2) + 5ns
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FIGURE 38. INTERRUPT PROCESS
ERROR CONDITION
OCCURS
Interrupt enable
bits at 0x60 and
0xn1 set?
NO
YES
Interrupt status bits
at
0x61 and 0xn2 set.
Interrupt Generated
INT pin goes "Low"
Interrupt Service
Routine
reads the status
register at 0x61
Interrupt Service
Routine
reads the status
register at 0xn2
Interrupt is being
serviced.
YES
NO
Interrupt Pending ?
48
INT pin goes "High"
Normal Operation
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7.2.1 Hardware Reset:
The hardware reset is initiated by pulling the RESET pin “Low” for a minimum of 5 µs. After the RESET pin is
released, the register values are put in default states.
TABLE 15: REGISTER MAP AND BIT NAMES
DATA BITS
ADDRESS
(HEX)
PARAMETER
NAME
0x00
APS/Redundancy #1
0x08
APS/ Redundancy #2
0x60
Interrupt Enable
(read/write)
Reserved
INTEN_5 INTEN_4 INTEN_3 INTEN_2 INTEN_1 INTEN_0
0x61
Interrupt Status
(read only)
Reserved
INTST_5
7
6
5
4
3
2
1
0
Reserved
TxON_5
TxON_4
TxON_3
TxON_2
TxON-1
TxON_0
Reserved
RxON_5
RxON_4
RxON_3
RxON_2
RxON_1
RxON_0
INTST_4
0x62 0x6D
INTST_3
INTST_2
INTST_1
INTST_0
1
0
1
Reserved
0x6E
Chip_id
(read only)
0x6F
Chip_revision _id
(read only)
0
1
1
1
0
Chip version number
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TABLE 16: REGISTER MAP DESCRIPTION - GLOBAL
ADDRESS
(HEX)
TYPE
0x00
R/W
REGISTER
NAME
APS # 1
DEFAULT
VALUE
SYMBOL
DESCRIPTION
TxON_n
Table below shows the status of the transmitter based
on the bit and pin setting.
Bit
Pin
Transmitter Status
0
0
OFF
0
1
OFF
1
0
OFF
1
1
ON
0
0x08
R/W
APS # 2
RxON_n
Set this bit to turn on individual Receiver.
0
0x60
R/W
Interrupt
Enable
INTEN_n
Set this bit to enable the interrupts on per channel
basis.
0
0x61
ROR
Interrupt
Status
INTST_n
Bits are set when an interrupt occurs.The respective
source level interrupt status registers are read to
determine the cause of interrupt.
0
0x62 0x6D
Reserved
0x6E
R
Device _ id
0x6F
R
Version
Number
Chip_id
This read only register contains device id.
01110101
Chip_version This read only register contains chip version number
TABLE 17: REGISTER MAP AND BIT NAMES - CHANNEL N REGISTERS (N = 0,1,2,3,4,5)
ADDRESS
(HEX)
PARAMETER
NAME
0x01 (ch 0)
0x11 (ch 1)
0x21 (ch 2)
0x31 (ch 3)
0x41 (ch 4)
0x51 (ch 5)
Interrupt
Enable
(read/write)
0x02 (ch 0)
Interrupt
0x12 (ch 1)
Status
0x22 (ch 2) (reset on read)
0x32 (ch 3)
0x42 (ch 4)
ox52 (ch 5)
DATA BITS
7
6
5
4
3
2
1
0
Reserved
PRBSER PRBSERI
CNTIE_n
E_n
FLIE_n
RLOLIE_n RLOSIE_ DMOIE_n
n
Reserved
PRBSER PRBSERI
CNTIS_n
S_n
FLIS_n
RLOLIS_n RLOSIS_ DMOIS_n
n
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TABLE 17: REGISTER MAP AND BIT NAMES - CHANNEL N REGISTERS (N = 0,1,2,3,4,5)
ADDRESS
(HEX)
0x03 (ch 0)
0x13 (ch 1)
0x23 (ch 2)
0x33 (ch 3)
0x43 (ch 4)
0x53 (ch 5)
PARAMETER
NAME
DATA BITS
7
6
5
Alarm Status Reserved PRBSLS_n DLOS_n
(read only)
4
3
2
1
0
ALOS_n
FL_n
RLOL_n
RLOS_n
DMO_n
0x04 (ch 0)
0x14 (ch 1)
0x24 (ch 2)
0x34 (ch 3)
0x44 (ch 4)
0x54 (ch 5)
Transmit
Control
(read/write)
Reserved
TxMON_n INSPRBS Reserved
_n
0x05 (ch 0)
0x15 (ch 1)
0x25 (ch 2)
0x35 (ch 3)
0x45 (ch 4)
0x55 (ch 5)
Receive
Control
(read/write)
Reserved
DLOSDIS ALOSDIS RxCLKIN LOSMUT_ RxMON_n REQEN_
_n
_n
V_n
n
n
0x06 (ch 0)
0x16 (ch 1)
0x26 (ch 2)
0x36 (ch 3)
0x46 (ch 4)
0x56 (ch 5)
Block Control Reserved CLKOUTE PRBSEN_
(read/write)
N_n
0
RLB_n
LLB_n
TAOS_n
TxCLKINV TxLEV_n
_n
E3_n
STS1/
DS3_n
SR/DR_n
JA1_n
JATx/Rx_n
JA0_n
0x07 (ch 0)
0x17 (ch 1)
0x27 (ch 2)
0x37 (ch 3)
0x47 (ch 4)
0x57 (ch 5)
Jitter
Attenuator
Control
(read/write)
0x0A (ch 0)
0x1A (ch 1)
0x2A (ch 2)
0x3A (ch 3)
0x4A (ch 4)
0x5A (ch 5)
PRBS Error
Count Reg.
MSB
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
0x0B (ch 0)
0x1B (ch 1)
0x2B (ch 2)
0x3B (ch 3)
0x4B (ch 4)
0x5B (ch 5)
PRBS Error
Count Reg.
LSB
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reserved
DFLCK_n PNTRST_
n
0x0C (ch 0) PRBS Error
0x1C (ch 1) Count Holding
0x2C (ch 2)
Register
0x3C (ch 3)
0x4C (ch 4)
0x5C (ch 5)
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TABLE 18: REGISTER MAP DESCRIPTION - CHANNEL N
ADDRESS
(HEX)
0x01 (ch 0)
0x11 (ch 1)
0x21 (ch 2)
0x31 (ch 3)
0x41 (ch 4)
0x51 (ch 5)
TYPE
R/W
REGISTER
NAME
Interrupt
Enable
(source
level)
SYMBOL
DESCRIPTION
D0
DMOIE_n
If the Driver Monitor (connected to the output of the
channel) detects the absence of pulses for 128 consecutive cycles, it will set the interrupt flag if this bit
has been set.
0
D1
RLOSIE_n This flag will allow a loss of receive signal(for that
channel) to send an interrupt to the Host when this
bit is set.
0
D2
RLOLIE_n This flag will allow a loss of lock condition to send an
interrupt to the Host when this bit is set.
0
D3
FLIE_n
Set this bit to enable the interrupt when the FIFO
Limit of the Jitter Attenuator is within 2 bits of overflow/underflow condition.
NOTE: This bit field is ignored when the Jitter Attenuator is disabled.
0
D4
PRBSERIE Set this bit to enable the interrupt when the PRBS
_n
error is detected.
0
D5
PRBSERC Set this bit to enable the interrupt when the PRBS
NTIE_n
error count register saturates.
0
D6-D7
0x02 (ch 0) Reset Interrupt
0x12 (ch 1)
on
Status
0x22 (ch 2) Read (source
0x32 (ch 3)
level)
0x42 (ch 4)
0x52 (ch 5)
DEFAULT
VALUE
BIT#
Reserved
D0
DMOIS_n
If the Drive monitor circuot detects the absence of
pulses for 128 consecutive cycles, t will set this
interrupt status flag (if enabled) This bit is set on a
change of state of the DMO circuit.
0
D1
RLOSIS_n This flag will indicate a change of “loss of Receive
signal” to the Host when this bit is set.
0
D2
RLOLIS_n This flag will allow a change in the loss of lock condition to send an interrupt to the Host when this bit is
enabled.Loss of lock is defined as a difference of
greater than 0.5% between the recovered clock and
the channel’s reference clock. Any change (return to
lock) will trigger the interrupt status flag again.
0
D3
FLIS_n
This bit will generate an interrupt if the jitter attenuator FIFO reaches (or leaves) a limit condition. This
limit condition is defined as the FIFO being within
two counts of full or empty.
0
D4
PRBSERIS This bit is set when the PRBS error occurs.
_n
0
D5
PRBSERC This bit is set when the PRBS error count register
NTIS_n
saturates.
0
D7-D6
Reserved
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TABLE 18: REGISTER MAP DESCRIPTION - CHANNEL N
ADDRESS
(HEX)
0x03 (ch 0)
0x13 (ch 1)
0x23 (ch 2)
0x33 (ch 3)
0x43 (ch 4)
0x53 (ch 5)
TYPE
REGISTER
NAME
DEFAULT
VALUE
BIT#
SYMBOL
DESCRIPTION
D0
DMO_n
This bit is set when no transitions on the TTIP/
TRING have been detected for 128 ± 32 TxCLK
periods.It will be cleared when pulses resume.
0
D1
RLOS_n
This bit is set every time the receiver declares an
LOS condition.It will be cleared when the signal is
recognized again.
0
D2
RLOL_n
This bit is set when the detected clock is greater
than 0.5% oof frequency from the reference clock.By
definition, the two frequencies are “not in lock” with
each other. It will be cleared when they are “in lock”
again..
0
D3
FL_n
This bit is set when the FIFO reaches its limit.The
limit is defined to be within two bits of either underflow or overflow.
0
D4
ALOS_n
This bit is set when the receiver declares that the
Analog signal has degraded to the point that the signal has been lost.
0
D5
DLOS_n
This bit is set when no input signals have been
received for 10 to 255 bit times in E3 or 100 to 250
bit times in DS3 or STS-1 modes.This is a complete
lack of incoming pulses rather than signal attenuation (ALOS). It should be noted that this time period
is built into the Analog detector for E3 mode. Even
though DS3/STS-1 mode does not require analog
detection level, but it is provided and could help to
determine the “quality of the line” for DS/STS-1
applications.
0
PRBSLS_n This bit is set when the PRBS detector has been
enabled and it is not in sync with the incoming data
pattern. Once the sync is achieved, it will be cleared.
0
Read Alarm StaOnly tus
D6
D7
Reserved
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TABLE 18: REGISTER MAP DESCRIPTION - CHANNEL N
ADDRESS
(HEX)
TYPE
REGISTER
NAME
BIT#
SYMBOL
DESCRIPTION
D0
TxLEV_n
This bit should be set when the transmitter is driving
a line greater than 225 feet in the DS3 or STS-1
modes. It is not active in E3 mode.
D1
0x04 (ch 0)
0x14 (ch 1)
0x24 (ch 2)
0x34 (ch 3)
0x44 (ch 4)
0x54 (ch 5)
R/W
Transmit
Control
D2
TxCLKINV Set this bit to sample the data on TPOS/TNEG pins
_n
on the rising edge of TxCLK.Default is to sample on
the falling edge of TxCLK.
TAOS_n
This bit should be set to transmit a continuous “all
ones” data pattern. Timing will come from TxCLK if
available otherwise from channel refernce clock.
D3
R/W
0
0
0
Reserved
D4
INSPRBS_ This bit causes a single bit error to be inserted in the
n
transmitted PRBS pattern if the PRBS generator/
detector has been enabled.
0
D5
TxMON_n When set, this bit enables the DMO circuit to monitor its own channel’s transmit driver. Otherwise, it
uses the MTIP/MRING pins to monitor another
channel or device.
0
D7-D6
0x05 (ch 0)
0x15 (ch 1)
0x25 (ch 2)
0x35 (ch 3)
0x45 (ch 4)
0x55 (ch 5)
DEFAULT
VALUE
Reserved
D0
REQEN_n This bit enables the Receiver Equalizer. When set,
the equalizer boosts the high frequency components
of the signal to make up for cable losses.
NOTE: See section 5.01 for detailed description.
0
D1
RxMON_n Set this bit to place the Receiver in the monitoring
mode. In this mode, it can process signals (at RTIP/
RRING) with 20dB of flat loss. This mode allows the
channel to act as monitor of aline without loading the
circuit.
0
D2
LOSMUT_ When set, the data on RPOS/RNEG is forced to
n
zero when LOS occurs. Thus any residual noise on
the line is not output as spurious data.
NOTE: If this bit has been set, it will remain set evan
after the LOS condition is cleared.
0
D3
RxCLKINV When this bit is set, RPOS and RNEG will change
_n
on the falling edge of RCLK.Default is for the data to
change on the rising edge of RCLK and be sampled
by the terminal equipment on the falling edge of
RCLK.
0
D4
ALOSDIS_ This bit is set to disable the ALOS detector. This flag
n
and the DLOSDIS are normally used in diagnostic
mode. Normal operation of DS3 and STS-1 would
have ALOS disabled.
0
D5
DLOSDIS_ This bit disables the digital LOS detector. This would
n
normally be disabled in E3 mode as E3 is a function
of the level of the input.
0
Receive
Control
D7-D6
Reserved
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TABLE 18: REGISTER MAP DESCRIPTION - CHANNEL N
ADDRESS
(HEX)
0x06 (ch 0)
0x16 (ch 1)
0x26 (ch 2)
0x36 (ch 3)
0x46 (ch 4)
0x56 (ch 5)
TYPE
R/W
REGISTER
NAME
Block Control
DEFAULT
VALUE
BIT#
SYMBOL
DESCRIPTION
D0
SR/DR_n
Setting this bit configures the Receiver and Transmitter in Single-Rail (NRZ) mode.
NOTE: See section 4.0 for detailed description.
0
D1
STS-1/
DS3_n
Setting this bit configures the channel into STS-1
mode.
NOTE: This bit field is ignored if the channel is configured to operate in E3 mode.
0
D2
E3_n
Setting this bit configures the channel in E3 mode.
0
D3
LLB_n
Setting this bit configures the channel in Local Loopback mode.
0
D4
RLB_n
This bit along with LLB_n determine the diagnostic
mode as shown in the table below.
0
RLB_n
LLB_n
Loopback Mode
0
0
Normal Operation
0
1
Analog Local
1
0
Remote
1
1
Digital
D5
PRBSEN_ Setting this bit enables the PRBS generator/detecn
tor. When in E3 mode, an unframed 223-1 pattern is
used. For DS3 and STS-1, unframed 215-1 pattern is
used. This mode of operation will use TCLK for timing. One should insure that a stable frequency is
provided. Looping this signal back to its own receive
channel and using RCLK to generate TCLK will
cause an unstable condition and should be avoided.
0
D6
CLKOUTE Set this bit to enable the CLKOUTs on a per channel
N_n
basis. The frequency of the output clock is dependent on the configuration of the channels, either E3,
DS3 or STS-1.
0
D7
Reserved
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TABLE 18: REGISTER MAP DESCRIPTION - CHANNEL N
ADDRESS
(HEX)
0x07 (ch 0)
0x17 (ch 1)
0x27 (ch 2)
0x37 (ch 3)
0x47 (ch 4)
0x57 (ch 5)
TYPE
R/W
REGISTER
NAME
DEFAULT
VALUE
BIT#
SYMBOL
DESCRIPTION
D0
JA0_n
This bit along with JA1_n bit configures the Jitter
Attenuator as shown in the table below.
JA0_n
JA1_n
Mode
0
0
16 bit FIFO
0
1
Jitter
Attenuator
D1
D2
D3
D4
1
0
1
1
32 bit FIFO
Disable Jitter
Attenuator
Disable Jitter
Attenuator
JATx/Rx_n Setting this bit selects the Jitter Attenuator in the
Transmit Path. A “0” selects in the Receive Path.
JA1_n
0
0
This bit along with the JA0_n configures the Jitter
Attenuator as shown in the table.
0
PNTRST_n Setting this bit resets the FIFO pointers to their initial
state and flushes the FIFO. All existing FIFO data is
lost.
0
DFLCK_n
Set this bit to “1” to disable fast locking of the PLL.
This helps to reduce the time for the PLL to lock to
incoming frequency when the Jitter Attenuator
switches to narrow band.
D7-D5
Reserved
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SIX CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
8.0 ELECTRICAL CHARACTERISTICS
TABLE 19: ABSOLUTE MAXIMUM RATINGS
SYMBOL
PARAMETER
MIN
MAX
UNITS
COMMENTS
VDD
Supply Voltage
-0.5
6.0
V
Note 1
VIN
Input Voltage at any Pin
-0.5
5.5
V
Note 1
IIN
Input current at any pin
100
mA
Note 1
STEMP
Storage Temperature
-65
150
0
C
Note 1
ATEMP
Ambient Operating Temperature
-40
85
0
C
linear airflow 0 ft./min
Theta JA
Thermal Resistance
C/W
linear air flow 0ft/min
23
0
(See Note 3 below)
MLEVL
Exposure to Moisture
4
level
EIA/JEDEC
JESD22-A112-A
ESD
ESD Rating
2000
V
Note 2
NOTES:
1. Exposure to or operating near the Min or Max values for extended period may cause permanent failure and impair
reliability of the device.
2. ESD testing method is per MIL-STD-883D,M-3015.7
3. With Linear Air flow of 200 ft/min, reduce Theta JA by 20%, Theta JC is unchanged.
TABLE 20: DC ELECTRICAL CHARACTERISTICS:
PARAMETER
SYMBOL
MIN.
TYP.
MAX.
UNITS
DVDD
Digital Supply Voltage
3.135
3.3
3.465
V
AVDD
Analog Supply Voltage
3.135
3.3
3.465
V
ICC
Supply current requirements
725
850
mA
PDD
Power Dissipation
2.64
2.93
W
VIL
Input Low Voltage
0.8
V
VIH
Input High Voltage
5.5
V
VOL
Output Low Voltage, IOUT = - 4mA
0.4
V
VOH
Output High Voltage, IOUT = 4 mA
2.0
2.4
V
IL
Input Leakage Current1
±10
µA
CI
Input Capacitance
10
pF
CL
Load Capacitance
10
pF
NOTES:
1.
Not applicable for pins with pull-up or pull-down resistors.
2. The Digital inputs are TTL 5V compliant.
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APPENDIX - A
TABLE 21: TRANSFORMER RECOMMENDATIONS
PARAMETER
VALUE
Turns Ratio
1:1
Primary Inductance
40 µH
Isolation Voltage
1500 Vrms
Leakage Inductance
0.6 µH
TABLE 22: TRANSFORMER DETAILS
PART NUMBER
VENDOR
INSULATION
PACKAGE TYPE
PE-68629
PULSE
3000 V
Large Thru-hole
PE-65966
PULSE
1500 V
Small Thru-hole
PE-65967
PULSE
1500 V
SMT
T 3001
PULSE
1500 V
SMT
TG01-0406NS
HALO
1500 V
SMT
TTI 7601-SM
TransPower
1500 V
SMT
TRANSFORMER VENDOR INFORMATION
Pulse
Corporate Office
12220 World Trade Drive
San Diego, CA 92128
Tel: (858)-674-8100
FAX: (858)-674-8262
Europe
1 & 2 Huxley Road
The Surrey Research Park
Guildford, Surrey GU2 5RE
United Kingdom
Tel: 44-1483-401700
FAX: 44-1483-401701
Halo Electronics
Corporate Office
P.O. Box 5826
Redwood City, CA 94063
Tel: (650)568-5800
FAX: (650)568-6165
Email: info@haloelectronics.com
Website: http://www.haloelectronics.com
Transpower Technologies, Inc.
Corporate Office
Park Center West Building
9805 Double R Blvd, Suite # 100
Reno, NV 89511
(800)500-5930 or (775)852-0140
Email: info@trans-power.com
Website: http://www.trans-power.com
Asia
150 Kampong Ampat
#07-01/02
KA Centre
Singapore 368324
Tel: 65-287-8998
Website: http://www.pulseeng.com
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ORDERING INFORMATION
PART NUMBER
PACKAGE
OPERATING TEMPERATURE RANGE
XRT75R06IB
217 Lead BGA (23 x 23 mm)
- 40°C to + 85°C
PACKAGE DIMENSIONS - 23 X 23 MM 217 LEAD BGA PACKAGE
BOTTOM VIEW
(A1 corner feature is mfger option)
β
Note: The control dimension is in millimeter.
SYMBOL
A
A1
A2
A3
D
D1
D2
b
e
β
INCHES
MIN
MAX
0.067
0.098
0.016
0.028
0.012
0.024
0.039
0.047
0.898
0.913
0.800 BSC
0.780
0.795
0.024
0.035
0.050 BSC
10°
20°
59
MILLIMETERS
MIN
MAX
1.70
2.50
0.40
0.70
0.30
0.60
1.00
1.20
22.80
23.20
20.32 BSC
19.80
20.20
0.60
0.90
1.27 BSC
10°
20°
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REVISIONS
REVISION
DATE
COMMENTS
P1.0.0
06/11/04
First release of the preliminary datasheet.
P1.0.1
07/15/04
Second release of the preliminary datasheet.
1.0.0
12/14/04
Release to production. Entered power dissapation and power supply current in electrical.
NOTICE
EXAR Corporation reserves the right to make changes to the products contained in this publication in order to
improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any
circuits described herein, conveys no license under any patent or other right, and makes no representation that
the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration
purposes and may vary depending upon a user’s specific application. While the information in this publication
has been carefully checked; no responsibility, however, is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where the
failure or malfunction of the product can reasonably be expected to cause failure of the life support system or
to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless
EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has
been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately
protected under the circumstances.
Copyright 2004 EXAR Corporation
Datasheet December 2004.
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
60
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