SEMTECH ACS8595T

ACS8595 ATCA
Line Card Protection Switch for
SONET/SDH AdvancedTCA Systems
ADVANCED COMMUNICATIONS
Description
FINAL
Features
The ACS8595 ATCA is a highly integrated, single-chip
solution for “Hit-less” protection switching of SEC
(SDH/SONET Equipment Clock) + Sync clock “Groups”,
from Master and Slave SETS clock cards and a third
(Stand-by) source, for line cards/blades in a SONET or
SDH ATCA (Advanced Telecommuncications Computing
Architecture) Network Element. The ACS8595 has fast
activity monitors on the SEC clock inputs and will
implement automatic system protection switching against
the Master clock failure. The selection of the
Master/Slave input can be forced by a Force Fast Switch
pin. If both the Master and Slave input clocks fail, the
Stand-by “Group” is selected or, if no Stand-by is
available, the device enters Digital Holdover mode.
The ACS8595 can perform frequency translation,
converting, for example, an 8 kHz SEC input clock from
the ATCA backplane into a range of spot frequencies from
2 kHz up to 311.04 MHz (up to 77.76 MHz on the
TTL/CMOS ports). The output frequency is independently
programmable on each of the six SEC output ports, so the
ACS8595 ATCA has the potential to supply simultanously
up to six different SEC frequencies, for example, to meet
the individual requirements of several Advanced
Mezzanine Cards (AMCs).
The ACS8595 has one PECL/LVDS output port and five
TTL/CMOS ports. It also provides an 8 kHz Frame Sync
and a 2 kHz Multi-Frame Sync TTL/CMOS signal output
with programmable pulse width and polarity.
The ACS8595 includes a Serial Port, which can be SPI
compatible, providing access to the configuration and
status registers for device setup.
Block Diagram
PRODUCT BRIEF
‹ SONET/SDH applications up to OC-3/STM-1 bit rates
‹ Switches between grouped inputs (SEC/Sync pairs)
‹ Inputs: three SECs at any of 2, 4, 8 kHz (and N x 8 kHz
multiples up to 155.52 MHz), plus Frame Sync/MultiFrame Sync
‹ Outputs: Six SEC clocks at any of several spot frequencies from 2 kHz up to 77.76 MHz via the TTL/CMOS
port and up to 311.04 MHz via the PECL/LVDS port
‹ Modes for E3/DS3 and multiple E1/DS1 rate output
clocks
‹ Generates 8 kHz Frame Sync and 2 kHz Multi-Frame
Sync output clocks with programmable pulse width
and polarity
‹ Frequency translation of SEC input clock to different
local line card clocks
‹ Robust activity monitoring on all clock inputs
‹ Supports Free-run, Locked and Digital Holdover
modes of operation
‹ Automatic “Hit-less” source switchover on loss of
input
‹ External force fast switch between SEC1/SEC2 inputs
‹ Phase Build-out for output clock phase continuity during input switchover
‹ PLL “Locked” and “Acquisition” bandwidths individually selectable from 18, 35 or 70 Hz
‹ Serial interface for device set-up
‹ IEEE 1149.1 JTAG Boundary Scan is supported.
‹ Single 3.3 V operation, 5 V I/O compatible
‹ Operating temperature (ambient) of -40 to +85°C
‹ Available in 100-pin LQFP package
‹ Lead (Pb)-free version (ACS8595T), RoHS and WEEE
compliant
Figure 1 Block Diagram of the ACS8595 ATCA
3 x SEC/Sync Input Groups
SEC1 & SEC2:
TTL/PECL/LVDS,
SEC3 and all Syncs
TTL only
SEC1
Master
SYNC1
SEC2
Slave
SYNC2
SEC3
SEC Outputs:
O1 (PECL/LVDS)
DPLL2
DPLL1
Input
SEC Port
Monitors
and
Input
Selection
Control
MUX
2
Selector
APLL3
SYNC3
SEC Inputs:
Programmable
Frequencies
2 kHz, 4 kHz,
TCK
N x 8 kHz
TDI
1.544/2.048 MHz
TMS
6.48 MHz
TRST
19.44 MHz
TDO
25.92 MHz
38.88 MHz
51.84 MHz
77.76 MHz
155.52 MHz
IEEE
1149.1
JTAG
Chip
Clock
Generator
Output
Port
Frequency
Selection
Digital Feedback
E1/DS1
Synthesis
Stand-by
APLL2
Priority Register Set
Table
TCXO or
XO
MUX
1
APLL 1
Serial Interface
Port
O2 (TTL)
O3 (TTL)
O4 (TTL)
O5 (TTL)
O6 (TTL)
Sync Outputs:
MFrSync 2 kHz (TTL)
FrSync 8 kHz (TTL)
01 TO O6:
8 kHz
1.544/2.048 MHz
3.088/4.096 MHz
6.176/8.192 MHz
12.352/16.384 MHz
6.48 MHz (not O1)
19.44 MHz
25.92 MHz
34.368 MHz
38.88 MHz
44.736 MHz
77.76 MHz
155.52 MHz (only O1)
311.04 MHz (only O1)
F8595_001BlockDia_01
Revision 2.00/October 2005 © Semtech Corp.
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
Pin Diagram
FINAL
Table 1 Power Pins (cont...)
Figure 2 ACS8595 Pin Diagram
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
SONSDHB
IC6
IC5
IC4
IC3
NC31
O6
O5
AGND4
VA3+
O2
O4
O3
DGND7
VDD7
VDD6
DGND6
SDO
NC30
NC29
NC28
NC27
TDI
TDO
TCK
Pin No.
AGND1
NC1
IC1
NC2
AGND2
VA1+
NC3
INTREQ
NC4
REFCLK
DGND1
VD1+
VD3+
DGND3
DGND2
VD2+
NC5
SRCSW
VA2+
AGND3
NC6
IC2
NC7
NC8
NC9
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
ACS8595 ATCA
SONET/SDH LC/P
NC26
PORB
SCLK
VDD5
VDD4
CSB
SDI
CLKE
TMS
NC25
NC24
NC23
NC22
DGND5
VDD3
NC21
TRST
VDD2
NC20
NC19
NC18
SYNC3
NC17
SEC3
SYNC2
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
NC10
NC11
NC12
NC13
FrSync
MFrSync
GND_DIFFa
VDD_DIFFa
O1POS
O1NEG
NC14
NC15
GND_DIFFb
VDD_DIFFb
SEC1POS
SEC1NEG
SEC2POS
SEC2NEG
VDD5V
SYNC1
SEC1
SEC2
NC16
DGND4
VDD1
1
2
3
4
5
6
7
8
9
10
11
1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
F8595LPB_002PINDIAG_02
Pin Description
Table 1 Power Pins
Pin No.
Symbol
I/O
Type
12,16,
13,
VD1+, VD2+,
VD3+
P
-
Supply Voltage: Digital supply to gates in
analog section, +3.3 Volts ±10%.
33,
39
VDD_DIFFa,
VDD_DIFFb
P
-
Supply Voltage: Digital supply for
differential output pins 19 and 20,
+3.3 Volts ±10%.
44
VDD5V
P
-
Digital Supply for +5 Volts Tolerance to
Input Pins. Connect to +5 Volts (±10%) for
clamping to +5 Volts. Connect to VDD for
clamping to +3.3 Volts. Leave floating for
no clamping. Input pins tolerant up to
+5.5 Volts.
Description
VDD1, VDD2,
VDD3, VDD4
VDD5, VDD6,
VDD7
P
6
VA1+
P
-
Supply Voltage: Analog supply to clock
multiplying PLL,
+3.3 Volts ±10%.
19, 91
VA2+, VA3+
P
-
Supply Voltage: Analog supply to output
PLLs APLL2 and APPL1, +3.3 Volts ±10%.
1,
5
AGND1,
AGND2
P
-
Supply Ground: Analog grounds.
Supply Voltage: Digital supply to logic,
+3.3 Volts ±10%.
Revision 2.00/October 2005 © Semtech Corp.
Symbol
20,
92
AGND3,
AGND4
11,
15,
14
DGND1,
DGND2,
DGND3
49,
62,
84,
87
32,
38
I/O
Type
Description
-
Supply Ground: Analog ground for output
PLLs APLL2 and APPL1.
P
-
Supply Ground: Digital ground for
components in PLLs.
DGND4,
DGND5,
DGND6,
DGND7
P
-
Supply Ground: Digital ground for logic.
GND_DIFFa,
GND_DIFFb
P
-
Supply Ground: Digital ground for
differential ports.
Note...I = Input, O = Output, P = Power, TTLU = TTL input with pull-up
resistor, TTLD = TTL input with pull-down resistor.
Table 2 Internally Connected and Not Connected Pins
Pin No.
Symbol
I/O
Type
3, 22, IC1, IC2,
96, 97, IC3, IC4,
98, 99 IC5, IC6,
-
-
Internally Connected: Leave to float.
2,4,
7,9,
17, 21,
23,24,
25,26,
27,28,
29, 36,
37, 48,
53, 55,
56, 57,
60, 63,
64, 65,
66, 75,
79,80,
81, 82,
95
-
-
Not Connected: Leave to float.
NC1, NC2,
NC3,NC4,
NC5,NC6,
NC7, NC8,
NC9, NC10,
NC11, NC12,
NC13,NC14,
NC15, NC16,
NC17, NC18,
NC19, NC20,
NC21, NC22,
NC23, NC24,
NC25, NC26,
NC27, NC28,
NC29, NC30,
NC31
Description
Table 3 Other Pins
50, 58,
61, 71
72, 85,
86
-
PRODUCT BRIEF
Pin No.
Symbol
I/O
Type
Description
8
INTREQ
O
TTL/CMOS
10
REFCLK
I
TTL
Reference Clock: 12.800 MHz.
18
SRCSW
I
TTLD
Source Switching: Force Fast Source
Switching on SEC1 and SEC2.
30
FrSync
O
TTL/CMOS
Output Reference: 8 kHz Frame Sync
output.
31
MFrSync
O
TTL/CMOS
Output Reference: 2 kHz Multi-Frame Sync
output.
34,
35
O1POS,
O1NEG
O
LVDS/PECL Output Reference: Programmable, default
38.88 MHz, LVDS.
Page 2
Interrupt Request: Active High/Low
software Interrupt output.
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
FINAL
Table 3 Other Pins (cont...)
Pin No.
PRODUCT BRIEF
Table 3 Other Pins (cont...)
Symbol
I/O
Type
Description
Pin No.
40,
41
SEC1_POS,
SEC1_NEG
I
PECL/LVDS Input Reference: Programmable, default
19.44 MHz, PECL.
83
42,
43
SEC2_POS,
SEC2_NEG
I
PECL/LVDS Input Reference: Programmable, default
19.44 MHz PECL.
45
SYNC1
I
TTLD
(Master) Multi-Frame Sync 2 kHz Input:
Connect to 2 or 8 kHz Multi-Frame Sync
output of Master SETS.
46
SEC1
I
TTLD
(Master) Input Reference: Programmable,
default 8 kHz.
47
SEC2
I
TTLD
(Slave) Input Reference: Programmable,
default 8 kHz.
51
SYNC2
I
TTLD
(Slave) Multi-Frame Sync 2 kHz: Connect to
2 or 8 kHz Multi-Frame Sync output of Slave
SETS.
52
SEC3
I
TTLD
(Stand-by) Input Reference: External standby reference clock source, programmable,
default 19.44 MHz.
54
SYNC3
I
TTLD
(Stand-by) Input Reference: External standby 2 or 8 kHz Multi-Frame Sync clock
source.
59
TRST
I
TTLD
JTAG Control Reset Input: TRST = 1 to
enable JTAG Boundary Scan mode. TRST =
0 is Boundary Scan stand-by mode, still
allowing normal device operation (JTAG
logic transparent). NC if not used.
67
TMS
I
TTLD
JTAG Test Mode Select: Boundary Scan
enable. Sampled on rising edge of TCK. NC
if not used.
68
CLKE
I
TTLD
SCLK Edge Select: SCLK active edge select,
CLKE = 1, selects falling edge of SCLK to be
active.
69
SDI
I
TTLD
Serial Interface Address: Serial Data Input.
70
CSB
I
TTLU
Chip Select (Active Low): This pin is
asserted Low by the microprocessor to
enable the microprocessor interface.
73
SCLK
I
TTLD
Serial Data Clock. When this pin goes High
data is latched from SDI pin.
74
PORB
I
TTLU
Power-On Reset: Master reset. If PORB is
forced Low, all internal states are reset
back to default values.
76
TCK
I
TTLD
JTAG Clock: Boundary Scan clock input.
77
TDO
O
TTL/CMOS
78
TDI
I
TTLD
I/O
Type
Description
SDO
O
TTLD
88
O3
O
TTL/CMOS
Output Reference: Programmable, disabled
by default.
89
O4
O
TTL/CMOS
Output Reference: Programmable, disabled
by default.
90
O2
O
TTL/CMOS
Output Reference: Programmable, default
19.44 MHz.
93
O5
O
TTL/CMOS
Output Reference: Programmable, disabled
by default.
94
O6
O
TTL/CMOS
Output Reference: Programmable, disabled
by default.
100
SONSDHB
I
TTLD
SONET or SDH Frequency Select: Sets the
initial power-up state (or state after a
PORB) of the SONET/SDH frequency
selection registers, Reg. 34, Bit 2 and
Reg. 38, Bit 5, Bit 6 and Reg. 64 Bit 4.
When set Low, SDH rates are selected
(2.048 MHz etc.) and when set High,
SONET rates are selected (1.544 MHz etc.)
The register states can be changed after
power-up by software.
Interface Address: SPI compatible Serial
Data Output.
Introduction
The ACS8595 ATCA is a Line Card Protection device
designed to complement the Semtech SETS devices
which maintain the SETS functions in both SONET and
SDH Network Elements. The ACS8595 ATCA extends this
functionality on to the Line Card, for which it has been
specifically designed. The ACS8595 ATCA uses “Hit-less”
group switching between Master and Slave inputs or a
third (Stand-by) input group, to generate and maintain
accurate and stable SEC and frame synchronization pulse
outputs for distribution on the Line Card, typically for
Advanced Mezzaninie Cards (AMCs) on AdvancedTCA
equipment.
The ACS8595 provides a simple, compact, yet flexible
solution, which can be easily tailored for use with a range
of transmission formats and rates, via software
configuration.
JTAG Output: Serial test data output.
Updated on falling edge of TCK.
JTAG Input: Serial test data Input. Sampled
on rising edge of TCK.
Revision 2.00/October 2005 © Semtech Corp.
Symbol
The ACS8595 employs various mechanisms to maintain
the integrity of its output clocks when its input clocks fail
or fall below the required specification levels. By
smoothing out the effects of these input anomalies, the
ACS8595 improves the overall stability and reliability of
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
FINAL
the downstream system synchronization, which
translates to improved quality of service.
PRODUCT BRIEF
Input frequencies supported range from 2, 4, 8 kHz (and
n x 8 kHz) up to 155.52 MHz. Common E1, DS1,
OC-3/STM-1 and sub-divisions are supported as spot
frequencies to which the DPLLs will directly lock. Any input
frequency, up to 100 MHz, that is a multiple of 8 kHz can
also be locked to via a built-in programmable divider.
Refer to Table 4 for details of each input port.
The key architectural advantage that the ACS8595 has
over traditional solutions is in the use of Digital Phase
Locked Loop (DPLL) technology for precise and
repeatable performance over temperature or voltage
variations and between parts.
Semtech can provide an Evaluation Board so that
designers can rapidly appraise the ACS8595 ATCA device
and see for themselves the benefits that a Semtech ATCA
solution can bring to their designs.
General Description
Input Locking Frequency Modes
Each input port has to be configured to receive the
expected input frequency. To achieve this, three Input
Locking Frequency Modes are provided: Direct Lock,
Lock8K and DivN.
SEC Activity Monitors
Inputs
The ACS8595 SETS device has input ports for clock
groups from three sources, typically Master, Slave and
Stand-by, where each clock group comprises one SEC and
optionally one Sync signal. This means that when any SEC
input changeover is made, the corresponding Sync signal
changeover is also made. Master and Slave SEC inputs to
the device support TTL/CMOS and PECL/LVDS. The
Stand-by SEC and three Sync inputs are TTL/CMOS only.
All the TTL/CMOS ports are 3 V and 5 V compatible (with
clamping if required by connecting the VDD5V pin).
A monitoring function constantly appraises the activity of
each input SEC, and reports anomalous behavior. Each of
the input monitors is individually configurable, allowing
flags or interrupts to be raised which can influence both
the operating state of the device, and which inputs are
available for selection by the PLL circuitry. Any Input SEC
which suffers a loss-of-activity will be declared as
unavailable.
Anomalies detected by the Activity Monitor are integrated
in a Leaky Bucket Accumulator. Occasional anomalies do
not cause the accumulator to cross the alarm setting
threshold, so the selected reference source is retained.
Table 4 Input Reference Source Selection and Priority Table
Port Name
Channel Number
Input Port Technology
Frequencies Supported
Default Priority
SEC1 TTL
0011
TTL/CMOS
Up to 100 MHz (see Note (i))
Default (SONET): 8 kHz Default (SDH): 8 kHz
2
SEC2 TTL
0100
TTL/CMOS
Up to 100 MHz (see Note (i))
Default (SONET): 8 kHz Default (SDH): 8 kHz
3
SEC1 DIFF
0101
PECL/LVDS
PECL default
Up to 155.52 MHz (see Note (ii))
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
0
SEC2 DIFF
0110
PECL/LVDS
PECL default
Up to 155.52 MHz (see Note (ii))
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
0
SYNC1
0111
TTL/CMOS
2/4/8 kHz auto-sensing
n/a
SYNC2
1000
TTL/CMOS
2/4/8 kHz auto-sensing
n/a
SEC3
1001
TTL/CMOS
Up to 100 MHz (see Note (i))
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
4
SYNC3
1010
TTL/CMOS
2/4/8 kHz auto-sensing
n/a
Notes: (i) TTL ports (compatible also with CMOS signals) support clock speeds up to 100 MHz, with the highest spot frequency being
77.76 MHz. The actual spot frequencies are: 2 kHz, 4 kHz, 8 kHz (and N x 8 kHz), 1.544 MHz (SONET)/2.048 MHz (SDH), 6.48 MHz,
19.44 MHz, 25.92 MHz, 38.88 MHz, 51.84 MHz, 77.76 MHz. SONET or SDH input rate is selected via Reg. 34 bit 2, ip_sonsdhb).
(ii) PECL and LVDS ports support the spot clock frequencies listed above plus 155.52 MHz (and 311.04 MHz for Output O1 only).
(iii) SEC1 TTL and SEC2 TTL ports are on pins SEC1 and SEC2. SEC1 DIFF (Differential) port uses pins SEC1POS and SEC1NEG, similarly
SEC2DIFF uses pins SEC2POS and SEC2NEG.
Revision 2.00/October 2005 © Semtech Corp.
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
FINAL
Persistent anomalies cause the alarm setting threshold to
be crossed and result in the selected SEC (and Sync)
being rejected.
There is one Leaky Bucket Accumulator per SEC input.
Each Leaky Bucket Accumulator can be programmed with
a Bucket ID (0 to 3) which assigns to the Leaky Bucket the
corresponding Leaky Bucket Configuration (from four
available Configurations). Each Leaky Bucket
Configuration comprises the following programmable
parameters:
z
z
z
z
Bucket size
Alarm trigger (set threshold)
Alarm clear (reset threshold)
Leak rate (decay rate
the Register Descriptions in the datasheet for advanced
features and more information.
DPLL1 Main Features
z
z
z
z
z
z
z
Phase Locked Loops (PLLs)
Figure 1 shows the PLL circuitry which comprises two
Digital PLLs (DPLL1 and DPLL2), two output multiplying
and filtering Analog PLLs (APLL1 and APLL2), output
frequency dividers in an Output Port Frequency Selection
block, a Synthesis block, multiplexers MUX1 and MUX2,
and a feedback Analog PLL (APLL3). These functional
blocks and their interconnections are highly configurable,
via register control, providing a range of output
frequencies and a choice of levels of jitter performance.
The DPLLs give a stable and consistent level of
performance that can be easily programmed for different
dynamic behavior or operating range. They are not
affected by operating conditions or silicon process
variations. Digital Synthesis is used to generate all
required SONET/SDH output frequencies. The digital logic
operates at 204.8 MHz that is multiplied up from the
external 12.800 MHz oscillator module. Hence the best
resolution of the output signals from the DPLLs is one
204.8 MHz cycle or 4.9 ns.
Both of the DPLLs’ outputs can be connected to
multiplying and filtering APLLs. The outputs of these
APLLs are divided making a number of frequencies
simultaneously available for selection at the output clock
ports. The various combinations of DPLL, APLL,
Multiplexer and divider configurations allow for
generation of a comprehensive set of frequencies, as
listed in Table 5 and Table 6.
z
z
z
z
z
z
z
z
z
Multiple E1 and DS1 outputs supported
Low jitter MFrSync (2 kHz) and FrSync (8 kHz) outputs
Multiple phase loss and multiple phase detectors
Direct PLL locking to common SONET/SDH input
frequencies or any multiple of 8 kHz
Automatic mode switching between Free-run, Locked
and Digital Holdover modes (states)
Fast detection on input failure and entry into Digital
Holdover mode (holds at the last good frequency
value)
Frequency translation between input and output rates
via direct digital synthesis
High accuracy digital architecture for stable PLL
dynamics combined with an APLL for low jitter final
output clocks
Non-revertive mode
Frame Sync pulse alignment
Selectable automatic DPLL bandwidth control (auto
selects either Locked bandwidth, or Acquisition
bandwidth), or Locked DPLL bandwidth
Two programmable bandwidth controls:
• Locked bandwidth: 18, 35 or 70 Hz
• Acquisition bandwidth: 18, 35 or 70 Hz
Programmable damping factor, (For optional faster
locking and peaking control) Factors = 1.2, 2.5, 5, 10
or 20
Programmable DPLL pull-in frequency range
Phase Build-out on source switching (hit-less source
switching), on/off
Freeze Phase Build-out, on/off
DPLL2 Main Features
The main features of DPLL2 are:
z
Always locked to DPLL1
Single programmable bandwidth control: 18, 35 or
70 Hz
Programmable damping factor, (For optional faster
locking and peaking control) Factors = 1.2, 2.5, 5, 10
or 20.
Digital feedback, on/off
Output frequency selection
Page 5
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z
z
z
DPLLs
DPLL1 is the more feature rich of the two DPLLs. The main
features of the two DPLLs are summarized here. Refer to
Revision 2.00/October 2005 © Semtech Corp.
PRODUCT BRIEF
z
ACS8595 ATCA
ADVANCED COMMUNICATIONS
z
z
z
z
FINAL
DS3/E3 support (44.736 MHz / 34.368 MHz)
independent of rates from DPLL1
• Low jitter E1/DS1 options independent of rates
from DPLL1
• Frequencies of n x E1/DS1 including 16 and 12 x
E1, and 16 and 24 x DS1 supported
• Squelched (clock off)
Can provide the source for the 2 kHz and 8 kHz
outputs available at Outputs 01 to 06
Can use its phase detector to measure the input
phase difference between two inputs
Selectable digital feedback, on/off
Either the software or an internal state machine controls
the operation of DPLL1. The state machine for DPLL2 is
very simple and cannot be manually/externally controlled.
One additional feature of DPLL2 is the ability to measure
a phase difference between two inputs.
DPLL1 always produces an output at 77.76 MHz to feed
the APLL, regardless of the frequency selected at the
output pins or the locking frequency (frequency at the
input of the Phase and Frequency Detector — PFD).
DPLL2 can be operated at a number of frequencies. This
is to enable the generation of extra output frequencies,
which cannot be easily related to 77.76 MHz. If DPLL2 is
enabled, it locks to the 8 kHz from DPLL1. This is because
all of the frequencies of operation of DPLL2 can be
divided to 8 kHz and this will ensure synchronization of
frequencies, from 8 kHz upwards, within the two DPLLs.
APLLs
PRODUCT BRIEF
individually selectable. Output 01 is a differential port
(pins O1POS and O1NEG), and can be selected PECL or
LVDS. All other outputs are TTL/CMOS.
Table 5 Output Port Frequencies and Technologies
Port Name
Output Port
Technology
Frequencies Supported
O1
LVDS/PECL
(LVDS default)
Frequencies as per Table 6
O2, O3, O4,
O5 and O6
TTL/CMOS
FrSync
TTL/CMOS
FrSync, 8 kHz programmable pulse width and
polarity, see Reg. 7C.
MFrSync
TTL/CMOS
MFrSync, 2 kHz programmable pulse width and
polarity, see Reg. 7C.
Table 6 Output Frequencies/Lowest Jitter Configuration
(Typical Conditions)
Frequency (MHz)
2 kHz
Jitter Level (typ)
rms (ps)
60
8 kHz
p-p (ns)
0.6
60
0.6
1.536
(not O5/O6)
250
1.5
1.544
(not O5/O6)
150
1.0
2.048
220
1.2
2.0586667
150
1.0
110
0.75
2.316
(not O5/O6)
2.7306667
220
1.2
110
1.0
3.088
110
0.75
3.728
110
1.0
3800
13
2.796
(not O5/O6)
4.096
via Digital1 or Digital2 (not O1)
4.296
(not O5/O6)
120
1.0
4.86
(not O5/O6)
60
0.6
5.728
120
1.0
6.144
250
1.5
6.176
150
1.0
6.48
60
0.6
There are three APLLs. APLL1 and APLL2 provide a lower
final output jitter reducing the 4.9 ns p-p jitter from the
digital down to 500 ps p-p and 60 ps rms as typical final
outputs measured broadband (from 10 Hz to 1 GHz). The
feedback APLL (APLL3) is selected by default; it provides
improved performance over the digital feedback.
8.192
220
1.2
8.2346667
760
2.6
Each APLL has its own divider. Each divider
simultaneously outputs a series of fixed ratios of its APLL
input. These divided outputs are available on Output Ports
O1 to O6.
Outputs
The ACS8595 delivers eight output signals on the
following ports: Six clocks, one each on ports O1 to O6;
and two Sync signals, on ports FrSync and MFrSync.
Outputs O1 to O6 are independent of each other and are
Revision 2.00/October 2005 © Semtech Corp.
9.264
110
0.75
10.922667
250
1.6
11.184
110
1.0
12.288
250
1.5
12.352
110
0.75
16.384
220
1.2
16.46933
760
2.6
17.184
120
1.0
18.528
110
0.75
19.44
60
0.6
21.84533
250
1.6
22.368
110
1.0
24.576
250
1.5
24.704
110
0.75
25.92
60
0.6
32.768
220
1.2
34.368
120
1.0
37.056
110
0.75
Page 6
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
FINAL
Table 6 Output Frequencies/Lowest Jitter Configuration
(Typical Conditions) (cont...)
Frequency (MHz)
38.88
Jitter Level (typ)
rms (ps)
60
44.736
p-p (ns)
110
1.0
250
1.5
(O5/O6 only)
49.152
(O1 only)
900
4.5
49.408
(O5/O6 only)
150
1.0
49.408
(O1 only)
760
2.6
60
0.6
65.536
(O5/O6 only)
220
1.2
65.536
(O1 only)
120
1.0
68.736
120
1.0
74.112
(O5/O6 only)
110
0.75
74.112
(O1 only)
110
0.75
77.76
60
0.6
89.472
(O5/O6 only)
110
1.0
98.304
(O1 only)
900
4.5
98.304
(O1 only)
900
4.5
98.816
(O1 only)
760
2.6
131.072
(O1 only)
250
1.6
137.472
(O5/O6 only)
120
1.0
148.224
(O1 only)
110
0.75
60
0.6
60
0.6
155.52
311.04
(O1 only)
replacement source is available. Digital Holdover
operates instantaneously, which means the DPLL freezes
at the frequency it was operating at the time of entering
Digital Holdover mode.
0.6
49.152
51.84
PRODUCT BRIEF
Input Selection Priorities
Each input SEC can be programmed with a priority
number (see Table 4) allowing references to be chosen
according to the highest priority valid input. Under normal
operation, the input SECs are selected automatically,
according to availability and in order of priority. For special
circumstances, such as chip or board testing, the
selection may be forced by configuration.
The priority table is initially defined by the default
configuration and can be changed via the Serial interface
by the Network Manager. In this way, when all the defined
sources are active and valid, the source with the highest
programmed priority is selected but, if this source fails,
the next-highest source is selected, and so on.
Table 4 gives details of the input reference ports. Specific
frequencies and priorities are set by configuration.
Modes of Operation
Ultra Fast Switching
The device has three principle modes of operation:
SEC inputs are monitored using a leaky bucket approach
to allow source qualification criterion to be monitored. A
reference source is normally disqualified after the leaky
bucket monitor thresholds have been crossed. An option
for a faster disqualification has been implemented so that
a loss of activity of just a few reference clock cycles will
raise an alarm and cause a reference switch.
z
Free-run
z
Locked
z
Digital Holdover
The Free-run mode is typically used following a power-onreset or a device reset before network synchronization
has been achieved. In the Free-run mode, the timing and
synchronization signals generated from the ACS8595 are
based on the 12.800 MHz clock frequency provided from
the external oscillator and are not synchronized to an
input SEC. The accuracy can be enhanced via software
calibration to within ±0.0196229 ppm.
The Locked mode is used when an input SEC has been
selected and the PLL has had time to lock. When the
Locked mode is achieved, the output signal is in phase
and is locked to the selected input SEC. The priority table
determines which input SEC is selected. When the
ACS8595 is in Locked mode, the output frequency and
phase follows that of the selected input SEC.
In Digital Holdover mode, the ACS8595 provides the
timing signals to maintain the Line Card when its currently
selected input source becomes invalid, and no other valid
Revision 2.00/October 2005 © Semtech Corp.
External Forced Fast Protection Switching
External Forced Fast Protection Switching mode, for fast
switching between inputs SEC1 or SEC2, can be triggered
directly from the dedicated pin SRCSW.
Restoration
Restoration of repaired reference sources is handled
carefully to avoid inadvertent disturbance of the output
clock. For this, the ACS8595 has two modes of operation;
Revertive and Non-revertive.
Sync Reference Sources
The ACS8595 provides the facility to have a Sync
reference source associated with each SEC.
Page 7
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
FINAL
PRODUCT BRIEF
Performance Benefits from DPLL/APLL Technology
The Sync inputs (SYNC1, SYNC2 and SYNC3) are used for
Frame Sync output alignment and can be 2, 4 or 8 kHz
(automatically detected frequency).
The use of Digital Phase Locked Loop technology ensures
precise and repeatable performance over temperature or
voltage variations, and between parts. The overall PLL
bandwidth, loop damping, pull-in range and frequency
accuracy are all determined by digital parameters that
provide a consistent level of performance. An Analog PLL
takes the signal from the DPLL output and provides a
lower jitter output. The APLL bandwidth is set four orders
of magnitude higher than the DPLL bandwidth. This
ensures that the overall system performance still
maintains the advantage of consistent behavior provided
by the digital approach.
As in all the Semtech ACS85xx series of parts supporting
such a mechanism, the Sync is treated as an additional
part of the SEC clock. The failure of a Sync input will never
cause a source disqualification. The Sync input is used to
internally align the generation of the output 2 kHz and
8 kHz Sync pulses.
Serial Interface
The ACS8595 device has an SPI compatible serial
interface, providing access to the configuration and
status registers for device set-up and monitoring.
Conformance
The DPLLs are clocked by the external oscillator module
therefore the Free-run or Digital Holdover frequency
stability is only determined by the stability of the external
oscillator module. This key advantage confines all
temperature critical components to one well defined and
pre-calibrated module, whose performance can be
chosen to match the application.
The ACS8595 is designed for use in Line Cards in Network
Elements which must meet the requirements of the
following specifications:
All performance parameters of the DPLLs are
programmable without the need to understand detailed
PLL equations. Bandwidth, damping factor and lock
range, for example, can all be set directly.
ITU: G. 736, G.742, G.812, G.813, G.824, K.41.
Telcordia: GR-253-CORE, GR-499-CORE, GR-1244-CORE.
ANSI: T1.101-1999.
ETSI: ETSI 300 462-3, ETSI 300 462-5.
A high level of phase and frequency accuracy is made
possible in the ACS8595 by an internal resolution of up to
54 bits and internal Holdover accuracy of up to
7.5 x 10-14 ppb (instantaneous).
Performance
Typical Application
Figure 3 Semtech’s Product Family Solution for a Typical SONET/SDH Architecture
Multiple Line cards
Line Card (0C-12, OC-48)
Recovered Clock
Master Clock
Master Sync
Slave Clock
Slave Sync
Stand-by Clock
Stand-by Sync
Frame Sync
Multi Frame Sync
ACS8515
ACS8525
ACS8526
ACS8527
ACS8595 ATCA
FRAMER
SERDES
E1/DS1
LINE
CARD
PROTECTION
To/from
SONET/SDH/PDH
Network
Clock
Distribution
ACS8942A
JAM PLL
Low Jitter/Low Skew
Low Jitter up to 622 MHz
Backplane
Slave Sync Card
Master Sync Card
Input CLK Sources
Config.
Priorities
mP/Serial Bus
SSM
Primary Ref.
Input/
output
CLK
Line
I/F
Unit
DATA
SETS
ACS8510
ACS8520
ACS8522
ACS8530
Priorities
TCLK
SSM Handling
Function
Output
CLKs
Clock
Distribution
DATA
SEC
SetsLinecardGenApp_08
Revision 2.00/October 2005 © Semtech Corp.
Page 8
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
Register Map
FINAL
PRODUCT BRIEF
Table 7 Register Map
Address
(hex)
Default
(hex)
Register Name
RO = Read Only
R/W = Read/Write
Data Bit
7 (MSB)
chip_id (RO)
00
chip_revision (RO)
test_register1 (R/W)
03
14
test_register2 (R/W)
04
12
sts_interrupts (R/W)
05
FF
06
3F
sts_current_DPLL_frequency,
see OC/OD
07
00
sts_interrupts (R/W)
08
10
Sync_alarm_
int
sts_operating_mode (RO)
09
01
Sync_alarm
sts_priority_table (RO)
6
5
4
3
4D
chip_id[7:0], 8 LSBs of Chip ID
01
21
chip_id[15:8], 8 MSBs of Chip ID
02
00
2
1
8K Edge
Polarity
Set to 0
0 (LSB)
chip_revision[7:0]
Phase_alarm
Resync_
analog
Disable_180
Set to 0
Set to 0
Do not use
status_SEC2_
DIFF
operating_
mode
status_SEC1_
DIFF
status_SEC2_
TTL
status_SEC1_
TTL
DPLL1_main_
ref_failed
status_SEC3
Bits [18:16] of sts_current_DPLL_frequency
DPLL2_Lock
DPLL1_freq_
soft_alarm
DPLL2_freq_
soft_alarm
DPLL1_operating_mode
0A
00
Highest priority validated source
Currently selected source
0B
00
3rd highest priority validated source
2nd highest priority validated source
sts_current_DPLL_frequency [7:0] 0C
00
(RO)
Bits [7:0] of sts_current_DPLL_frequency
[15:8] 0D 00
[18:16] 07
00
0E
00
sts_sources_valid (RO)
Bits [15:8] of sts_current_DPLL_frequencyy
Bits [18:16] of sts_current_DPLL_frequency
SEC2 DIFF
SEC1 DIFF
SEC2 TTL
SEC1 TTL
0F
00
sts_reference_sources (RO)
Alarm Status on inputs:
SEC1 & SEC2 TTL 11
22
SEC1 & SEC2 DIFF 12
22
SEC3 14
22
cnfg_ref_selection_priority (R/W) 19
SEC1 & SEC2 TTL
32
programmed_priority_SEC2_TTL
programmed_priority_SEC1_TTL
SEC1 & SEC2 DIFF 1A
00
programmed_priority_SEC2_DIFF
programmed_priority_SEC1_DIFF
SEC3 1C
04
cnfg_ref_source_frequency_
<input> (R/W), where <input> =
SEC1 TTL 22
00
divn_SEC1 TTL lock8k_SEC1
TTL
Bucket_id_SEC1 TTL
reference_source_frequency_SEC1 TTL
SEC2 TTL 23
00
divn_SEC2 TTL lock8k_SEC2
TTL
Bucket_id_SEC2 TTL
reference_source_frequency_SEC2 TTL
SEC1 DIFF 24
03
divn_SEC1
DIFF
lock8k_SEC1
DIFF
Bucket_id_SEC1 DIFF
reference_source_frequency_SEC1 DIFF
SEC2 DIFF 25
03
divn_SEC2
DIFF
lock8k_SEC2
DIFF
Bucket_id_SEC2 DIFF
reference_source_frequency_SEC2 DIFF
divn_SEC3
lock8k_SEC3
Bucket_id_SEC3
reference_source_frequency_SEC3
SEC3 28
03
cnfg_operating_mode (R/W)
32
00
force_select_reference_source
(R/W)
33
0F
cnfg_input_mode (R/W)
34
CA
cnfg_DPLL2_path (R/W)
35
A0
cnfg_differential_inputs (R/W)
36
03
cnfg_dig_outputs_sonsdh (R/W)
38
04
cnfg_digtial_frequencies (R/W)
39
08
cnfg_differential_output (R/W)
3A
C2
cnfg_auto_bw_sel
3B
98
SEC3
No Activity
SEC2 TTL
Phase Lock
SEC2 TTL
No Activity
SEC1 TTL
Phase Lock
SEC1 TTL
No Activity
SEC2 DIFF
Phase Lock
SEC2 DIFF
No Activity
SEC1 DIFF
Phase Lock
SEC1 DIFF
No Activity
SEC3
Phase Lock
SEC3
programmed_priority_SEC3
DPLL1_operating_mode
forced_select_SEC_input
auto_extsync_
en
phalarm_
timeout
XO_ edge
extsync_en
ip_sonsdhb
reversion_
mode
DPLL2_dig_
feedback
SEC2_DIFF_
PECL
dig2_sonsdh
digital2_frequency
SEC1_DIFF_
PECL
dig1_sonsdh
digital1_frequency
Output O1 _LVDS_PECL
DPLL1_lim_int
auto_BW_sel
Revision 2.00/October 2005 © Semtech Corp.
Page 9
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
FINAL
PRODUCT BRIEF
Table 7 Register Map (cont...)
Address
(hex)
Default
(hex)
Register Name
RO = Read Only
R/W = Read/Write
cnfg_nominal_frequency
[7:0] 3C
(R/W)
Data Bit
7 (MSB)
6
5
3
2
Bits[7:0] of cnfg_nominal_frequency
[15:8] 3D 99
Bits[15:8] of cnfg_nominal_frequency
cnfg_DPLL_freq_limit (R/W) [7:0] 41
76
cnfg_DPLL_freq_limit (R/W) [9:8] 42
00
cnfg_interrupt_mask (R/W) [7:0] 43
00
Set to 0
Set to 0
[15:8] 44
00
operating_
mode
main_ref_
failed
[23:16] 45
00
Sync_ip_alarm
[7:0]. 46
FF
[13:8] 47
3F
cnfg_monitors (R/W)
48
04
cnfg_registers_source_select
(R/W)
4B
00
cnfg_freq_lim_ph_loss
4D
cnfg_freq_divn (R/W)
4
99
1
0 (LSB)
Bits[7:0] of cnfg_DPLL_freq_limit
Bits[9:8] of
cnfg_DPLL_freq_limit
SEC2 DIFF
SEC1 DIFF
SEC2 TTL
SEC1 TTL
Set to 0
SEC3
divn_value [7:0] (divide Input frequency by n)
divn_value [13:8] (divide Input frequency by n)
los_flag_on_
TDO
ultra_fast_
switch
ext_switch
PBO_freeze
PBO_en
DPLL1_DPLL2
_select
freq_lim_ph_
loss
cnfg_upper_threshold_0 (R/W)
50
06
upper_threshold_0_value (Activity alarm, Config. 0, Leaky Bucket - set threshold)
cnfg_lower_threshold_0 (R/W)
51
04
lower_threshold_0_value (Activity alarm, Config. 0, Leaky Bucket - reset threshold)
Bucket_size_0_value (Activity alarm, Config. 0, Leaky Bucket - size)
cnfg_bucket_size_0 (R/W)
52
08
cnfg_decay_rate_0 (R/W)
53
01
decay_rate_0_value (Activity
alarm, Config. 0, Leaky Bucket leak rate)
cnfg_upper_threshold_1 (R/W)
54
06
upper_threshold_1_value (Activity alarm, Config. 1, Leaky Bucket - set threshold)
cnfg_lower_threshold_1 (R/W)
55
04
lower_threshold_1_value (Activity alarm, Config. 1, Leaky Bucket - reset threshold)
Bucket_size_1_value (Activity alarm, Config. 1, Leaky Bucket - size)
cnfg_bucket_size_1 (R/W)
56
08
cnfg_decay_rate_1 (R/W)
57
01
decay_rate_1_value (Activity
alarm, Config. 1, Leaky Bucket leak rate)
cnfg_upper_threshold_2 (R/W)
58
06
upper_threshold_2_value (Activity alarm, Config. 2, Leaky Bucket - set threshold)
cnfg_lower_threshold_2 (R/W)
59
04
lower_threshold_2_value (Activity alarm, Config. 2, Leaky Bucket - reset threshold)
Bucket_size_2_value (Activity alarm, Config. 2, Leaky Bucket - size)
cnfg_bucket_size_2 (R/W)
5A
08
cnfg_decay_rate_2 (R/W)
5B
01
cnfg_upper_threshold_3 (R/W)
5C
06
cnfg_lower_threshold_3 (R/W)
5D 04
cnfg_bucket_size_3 (R/W)
5E
08
cnfg_decay_rate_3 (R/W)
5F
01
cnfg_output_frequency (R/W)
60
Outputs O4 & 03
00
decay_rate_2_value (Activity
alarm, Config. 2, Leaky Bucket leak rate)
upper_threshold_3_value (Activity alarm, Config. 3, Leaky Bucket - set threshold)
lower_threshold_3_value (Activity alarm, Config. 3, Leaky Bucket - reset threshold)
Bucket_size_3_value (Activity alarm, Config. 3, Leaky Bucket - size)
decay_rate_3_value (Activity
alarm, Config. 3, Leaky Bucket leak rate)
output_freq_O4
output_freq_O3
OutputsO5 & O2 61
06
output_freq_O5
output_freq_O2
OutputsO1 & 06 62
80
output_freq_O1
output_freq_O6
(MFrSync/FrSync) 63
C0
cnfg_DPLL2_frequency (R/W)
64
00
cnfg_DPLL1_frequency (R/W)
65
01
MFrSync_en
FrSync_en
DPLL2_meas_
DPLL1_ph
APLL2_for_
DPLL1_E1/DS
1
DPLL2_frequency
DPLL1_freq_to_APLL2
DPLL1_frequency
cnfg_DPLL2_bw (R/W)
66
00
DPLL2_bandwidth
cnfg_DPLL1_locked_bw (R/W)
67
10
DPLL1_locked_bandwidth
cnfg_DPLL1_acq_bw (R/W)
69
11
cnfg_DPLL2_damping (R/W)
6A
13
cnfg_DPLL1_damping (R/W)
6B
13
DPLL1_PD2_gain_alog_8k
DPLL1_damping
cnfg_DPLL2_PD2_gain (R/W)
6C
C2
DPLL2_PD2_
gain_enable
DPLL2_PD2_gain_alog
DPLL2_PD2_gain_digital
cnfg_DPLL1_PD2_gain (R/W)
6D C2
DPLL1_PD2_
gain_enable
DPLL1_PD2_gain_alog
DPLL1_PD2_gain_digital
DPLL1_acquisition_bandwidth
DPLL2_PD2_gain_alog_8k
Revision 2.00/October 2005 © Semtech Corp.
Page 10
DPLL2_damping
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
FINAL
PRODUCT BRIEF
Table 7 Register Map (cont...)
Address
(hex)
Default
(hex)
Register Name
RO = Read Only
R/W = Read/Write
cnfg_phase_offset (R/W)
[7:0] 70
[15:8] 71
cnfg_PBO_phase_offset (R/W)
Data Bit
7 (MSB)
6
5
3
phase_offset_value [7:0]
00
phase_offset_value[15:8]
2
1
0 (LSB)
PBO_phase_offset
72
00
cnfg_phase_loss_fine_limit (R/W) 73
A2
fine_limit_en
noact_ph_loss
narrow_en
cnfg_phase_loss_coarse_limit
(R/W)
74
85
coarse_lim_
phaseloss_en
wide_range_
en
multi_ph_resp
cnfg_ip_noise_window (R/W)
76
06
ip_noise_
window_en
sts_current_phase (RO)
4
00
phase_loss_fine_limit
phase_loss_coarse_limit
[7:0] 77
00
current_phase[7:0]
[15:8] 78
00
current_phase[15:8]
cnfg_phase_alarm_timeout
(R/W)
79
32
cnfg_sync_pulses (R/W)
7A
00
2k_8k_from_
DPLL2
cnfg_sync_phase (R/W)
7B
00
Indep_FrSync/
MFrSync
cnfg_sync_monitor (R/W)
7C
2B
ph_offset_
ramp
cnfg_interrupt (R/W)
7D 02
cnfg_protection(R/W)
7E
timeout_value (in two-second intervals)
8k_invert
Sync_OC-N_
rates
Sync_phase_SYNC3
Sync_phase_SYNC2
2k_invert
2k_pulse
Sync_phase_SYNC1
Sync_monitor_limit
Interrupt
GPO_en
85
Revision 2.00/October 2005 © Semtech Corp.
8k_pulse
Interrupt
tristate_en
Interrupt
int_polarity
protection_value
Page 11
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ACS8595 ATCA
ADVANCED COMMUNICATIONS
Ordering Information
FINAL
PRODUCT BRIEF
Table 8 Parts List
Part Number
Description
ACS8595
ATCA Line Card Protection Switch for SONET/SDH AdvancedTCA Systems
ACS8595T
Lead (Pb)-free package version of ACS8595; RoHs and WEEE compliant
ACS8595 EVB
Evaluation Board and Software
Disclaimers
Life support- This product is not designed or intended for use in life support equipment, devices or systems, or other critical
applications. This product is not authorized or warranted by Semtech for such use.
Right to change- Semtech Corporation reserves the right to make changes, without notice, to this product. Customers are advised
to obtain the latest version of the relevant information before placing orders.
Compliance to relevant standards- Operation of this device is subject to the User’s implementation and design practices. It is the
responsibility of the User to ensure equipment using this device is compliant to any relevant standards.
Contacts
For Additional Information, contact the following:
Semtech Corporation Advanced Communications Products
E-mail:
[email protected]
[email protected]
Internet:
http://www.semtech.com
USA:
200 Flynn Road, Camarillo, CA 93012-8790
Tel: +1 805 498 2111,
Fax: +1 805 498 3804
FAR EAST: 11F, No. 46, Lane 11, Kuang Fu North Road, Taipei, R.O.C.
Tel: +886 2 2748 3380
Fax: +886 2 2748 3390
EUROPE:
Semtech Ltd., Units 2 and 3, Park Court, Premier Way,
Abbey Park Industrial Estate, Romsey, Hampshire, SO51 9DN
Tel: +44 (0)1794 527 600
Fax: +44 (0)1794 527 601
ISO9001
CERTIFIED
Revision 2.00/October 2005 © Semtech Corp.
Page 12
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