ISO2-CMOS ST-BUS FAMILY MT9171/72
Digital Subscriber Interface Circuit
Digital Network Interface Circuit
Data Sheet
Features
March 2006
•
Full duplex transmission over a single twisted pair
•
Selectable 80 or 160 kbit/s line rate
•
Adaptive echo cancellation
•
Up to 3 km (9171) and 4 km (9172)
•
ISDN compatible (2B+D) data format
•
Transparent modem capability
•
Frame synchronization and clock extraction
•
Zarlink ST-BUS compatible
•
Low power (typically 50 mW), single 5 V supply
Ordering Information
MT9171/72AE
22 Pin PDIP
MT9171/72AN
24 Pin SSOP
MT9171/72AP
28 Pin PLCC
MT9171/72APR
28 Pin PLCC
MT9171/72ANR
24 Pin SSOP
MT9171/72AE1
22 Pin PDIP*
MT9171/72AP1
28 Pin PLCC*
MT9171/72AN1
24 Pin SSOP*
MT9171/72APR1 28 Pin PLCC*
MT9171/72ANR1 24 Pin SSOP*
*Pb Free Matte Tin
Digital subscriber lines
•
High speed data transmission over twisted wires
•
Digital PABX line cards and telephone sets
•
80 or 160 kbit/s single chip modem
F0/CLD
C4/TCK
F0o/RCK
MS0
MS1
MS2
Reel
Reel
Description
•
CDSTi/
CDi
Reel
Reel
-40°C to +85°C
Applications
DSTi/Di
Tubes
Tubes
Tubes
Tape &
Tape &
Tubes
Tubes
Tubes
Tape &
Tape &
Transmit
Interface
Control
Register
Prescrambler
Differentially
Encoded Biphase
Transmitter
Scrambler
Transmit
Filter &
Line Driver
Address
Echo Canceller
Error
Signal
Echo Estimate
Master Clock
Phase Locked
LOUT
LOUT
DIS
VBias
Transmit
Timing
Transmit/
Clock
Receive
Timing &
Control
Sync Detect
The MT9171 (DSIC) and MT9172 (DNIC) are pin for
pin compatible replacements for the MT8971 and
MT8972, respectively. They are multi-function devices
capable of providing high speed, full duplex digital
transmission up to 160 kbit/s over a twisted wire pair.
They use adaptive echo-cancelling techniques and
transfer data in (2B+D) format compatible to the ISDN
basic rate. Several modes of operation allow an easy
interface to digital telecommunication networks
including use as a high speed limited distance modem
MUX
Precan
—
∑
DPLL
+
Receive
Filter
-1
+2
LIN
RegC
Status
Receive
OSC2
DSTo/Do
CDSTo/
CDo
Receive
Interface
DePrescrambler
Descrambler
VDD
VSS
Differentially
Encoded Biphase
Receiver
VBias VRef
Figure 1 - Functional Block Diagram
1
Zarlink Semiconductor Inc.
Zarlink, ZL and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc.
Copyright 1999-2006, Zarlink Semiconductor Inc. All Rights Reserved.
OSC1
MT9171/72
Data Sheet
with data rates up to 160 kbit/s. Both devices function identically but with the DSIC having a shorter maximum loop
reach specification. The generic "DNIC" will be used to reference both devices unless otherwise noted.
4
3
2
1
28
27
26
VDD
LIN
TEST
LOUT DIS
Precan
OSC1
OSC2
C4/TCK
F0o/RCK
DSTi/Di
DSTo/Do
MS2
NC
MS1
MS0
RegC
F0/CLD
NC
22 PIN PDIP
LOUT
VBias
VRef
MS2
MS1
MS0
RegC
NC
F0/CLD
CDSTi/CDi
CDSTo/CDo
VSS
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
VDD
LIN
TEST
LOUT DIS
Precan
OSC1
NC
OSC2
C4/TCK
F0o/RCK
DSTi/Di
DSTo/Do
5
6
7
8
9
10
11
•
12
13
14
15
16
17
18
22
21
20
19
18
17
16
15
14
13
12
1
2
3
4
5
6
7
8
9
10
11
25
24
23
22
21
20
19
NC
LOUT DIS
Precan
OSC1
OSC2
NC
C4/TCK
CDSTi/CDi
CDSTo/CDo
VSS
DSTo/Do
DSTi/Di
F0o/RCK
NC
LOUT
VBias
VRef
MS2
MS1
MS0
RegC
F0/CLD
CDSTi/CDi
CDSTo/CDo
VSS
VRef
VBias
LOUT
NC
VDD
LIN
TEST
The MT9171/72 is fabricated in Zarlink’s ISO2-CMOS process.
28 PIN PLCC
24 PIN SSOP
Figure 2 - Pin Connections
Pin Description
Pin #
Name
Description
22
24
28
1
1
2
LOUT
Line Out. Transmit Signal output (Analog). Referenced to VBias.
2
2
3
VBias
Internal Bias Voltage output. Connect via 0.33 µF decoupling capacitor to VDD.
3
3
4
VRef
Internal Reference Voltage output. Connect via 0.33 µF decoupling capacitor to
VDD.
4,5, 4,5,
6
6
5,7,
8
MS2-MS0 Mode Select inputs (Digital). The logic levels present on these pins select the
various operating modes for a particular application. See Table 1 for the
operating modes.
7
7
9
RegC
Regulator Control output (Digital). A 512 kHz clock used for switch mode power
supplies. Unused in MAS/MOD mode and should be left open circuit.
8
9
10
F0/CLD
Frame Pulse/C-Channel Load (Digital). In DN mode a 244 ns wide negative
pulse input for the MASTER indicating the start of the active channel times of the
device. Output for the SLAVE indicating the start of the active channel times of
the device. Output in MOD mode providing a pulse indicating the start of the Cchannel.
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Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
Pin Description (continued)
Pin #
Name
Description
12
CDSTi/
CDi
Control/Data ST-BUS In/Control/Data In (Digital). A 2.048 Mbit/s serial control
& signalling input in DN mode. In MOD mode this is a continuous bit stream at
the bit rate selected.
11
13
CDSTo/
CDo
Control/Data ST-BUS Out/Control/Data Out (Digital). A 2.048 Mbit/s serial
control & signalling output in DN mode. In MOD mode this is a continuous bit
stream at the bit rate selected.
11
12
14
VSS
12
13
15
DSTo/Do Data ST-BUS Out/Data Out (Digital). A 2.048 Mbit/s serial PCM/data output in
DN mode. In MOD mode this is a continuous bit stream at the bit rate selected.
13
14
16
DSTi/Di
14
15
17
F0o/RCK Frame Pulse Out/Receive Bit Rate Clock output (Digital). In DN mode a 244 ns
wide negative pulse indicating the end of the active channel times of the device
to allow daisy chaining. In MOD mode provides the receive bit rate clock to the
system.
15
16
19
C4/TCK
16
17
21
OSC2
Oscillator Output. CMOS Output.
17
19
22
OSC1
Oscillator Input. CMOS Input. D.C. couple signals to this pin. Refer to D.C.
Electrical Characteristics for OSC1 input requirements.
18
20
23
Precan
Precanceller Disable. When held to Logic ’1’, the internal path from LOUT to the
precanceller is forced to VBias thus bypassing the precanceller section. When
logic ’0’, the LOUT to the precanceller path is enabled and functions normally. An
internal pulldown (50 kΩ) is provided on this pin.
8,
18
1,6,
11,
18,
20,
25
NC
19
21
24
20
22
26
TEST
21
23
27
LIN
Receive Signal input (Analog).
22
24
28
VDD
Positive Power Supply (+5 V) input.
22
24
28
9
10
10
Negative Power Supply (0 V).
Data ST-BUS In/Data In (Digital). A 2.048 Mbit/s serial PCM/data input in DN
mode. In MOD mode this is a continuous bit stream at the bit rate selected.
Data Clock/Transmit Baud Rate Clock (Digital). A 4.096 MHz TTL compatible
clock input for the MASTER and output for the SLAVE in DN mode. For MOD
mode this pin provides the transmit bit rate clock to the system.
No Connection. Leave open circuit
LOUT DIS LOUT Disable. When held to logic “1”, LOUT is disabled (i.e., output = VBias). When
logic “0”, LOUT functions normally. An internal pulldown (50 kΩ) is provided on
this pin.
Test Pin.
Connect to VSS.
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Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
F0
C4
DSTi
B17
B16
B15
B14
B13
B12
B11
B10
B17
DSTo
B17
B16
B15
B14
B13
B12
B11
B10
B17
F0o
Channel Time 0
Figure 3 - DV Port - 80 kbit/s (Modes 2, 3, 6)
F0
C4
DSTi
B17
B16 B15 B14
B13 B12
B11 B10
B27
B26 B25 B24
B23 B22
B21 B20
B17
DSTo
B17
B16 B15 B14
B13 B12
B11 B10
B27
B26 B25 B24
B23 B22
B21 B20
B17
F0o
Channel Time 0
Channel Time 16
Figure 4 - DV Port - 160 kbit/s (Modes 2, 3, 6)
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Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
Functional Description
The MT9171/72 is a device which may be used in practically any application that requires high speed data
transmission over two wires, including smart telephone sets, workstations, data terminals and computers. The
device supports the 2B+D channel format (two 64 kbit/s B-channels and one 16 kbit/s D-channel) over two wires as
recommended by the CCITT. The line data is converted to and from the ST-BUS format on the system side of the
network to allow for easy interfacing with other components such as the S-interface device in an NT1 arrangement,
or to digital PABX components.
Smart telephone sets with data and voice capability can be easily implemented using the MT9171/72 as a line
interface. The device’s high bandwidth and long loop length capability allows its use in a wide variety of sets. This
can be extended to provide full data and voice capability to the private subscriber by the installation of equipment in
both the home and central office or remote concentration equipment. Within the subscriber equipment the
MT9171/72 would terminate the line and encode/ decode the data and voice for transmission while additional
electronics could provide interfaces for a standard telephone set and any number of data ports supporting standard
data rates for such things as computer communications and telemetry for remote meter reading. Digital
workstations with a high degree of networking capability can be designed using the DNIC for the line interface,
offering up to 160 kbit/s data transmission over existing telephone lines. The MT9171/72 could also be valuable
within existing computer networks for connecting a large number of terminals to a computer or for intercomputer
links. With the DNIC, this can be accomplished at up to 160 kbit/s at a very low cost per line for terminal to
computer links and in many cases this bandwidth would be sufficient for computer to computer links.
Figure 1 shows the block diagram of the MT9171/72. The DNIC provides a bidirectional interface between the DV
(data/voice) port and a full duplex line operating at 80 or 160 kbit/s over a single pair of twisted wires. The DNIC has
three serial ports. The DV port (DSTi/Di, DSTo/Do), the CD (control/data) port (CDSTi/CDi, CDSTo/CDo) and a line
port (LIN, LOUT). The data on the line is made up of information from the DV and CD ports. The DNIC must combine
information received from both the DV and CD ports and put it onto the line. At the same time, the data received
from the line must be split into the various channels and directed to the proper ports. The usable data rates are 72
and 144 kbit/s as required for the basic rate interface in ISDN. Full duplex transmission is made possible through
on board adaptive echo cancellation.
The DNIC has various modes of operation which are selected through the mode select pins MS0-2. The two major
modes of operation are the MODEM (MOD) and DIGITAL NETWORK (DN) modes. MOD mode is a transparent 80
or 160 kbit/s modem. In DN mode the line carries the B and D channels formatted for the ISDN at either 80 or 160
kbit/s. In the DN mode the DV and CD ports are standard ST-BUS and in MOD mode they are transparent serial
data streams at 80 or 160 kbit/s. Other modes include: MASTER (MAS) or SLAVE (SLV) mode, where the timebase
and frame synchronization are provided externally or are extracted from the line and DUAL or SINGLE (SINGL)
port modes, where both the DV and CD ports are active or where the CD port is inactive and all information is
passed through the DV port. For a detailed description of the modes see “Operating Modes” section.
In DIGITAL NETWORK (DN) mode there are three channels transferred by the DV and CD ports. They are the B, C
and D channels. The B1 and B2 channels each have a bandwidth of 64 kbit/s and are used for carrying PCM
encoded voice or data. These channels are always transmitted and received through the DV port (Figures 3, 4, 5,
6). The C-channel, having a bandwidth of 64 kbit/s, provides a means for the system to control the DNIC and for the
DNIC to pass status information back to the system. The C-channel has a Housekeeping (HK) bit which is the only
bit of the C-channel transmitted and received on the line. The 2B+D channel bits and the HK bit are doublebuffered. The D-channel can be transmitted or received on the line with either an 8, 16 or 64 kbit/s bandwidth
depending on the DNIC’s mode of operation. Both the HK bit and the D-channel can be used for end-to-end
signalling or low speed data transfer. In DUAL port mode the C and D channels are accessed via the CD port
(Figure 7) while in SINGL port mode they are transferred through the DV port (Figures 5, 6) along with the B1 and
B2 channels.
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Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
F0
C4
DSTo
D0 D1 D2 D3 D4 D5 D6 D7 C0 C1 C2 C3 C4 C5 C6 C7
B7 B6 B5 B4 B3 B2 B1 B0
D0
D0 D1 D2 D3 D4 D5 D6 D7 C0 C1 C2 C3 C4 C5 C6 C7
B7 B6 B5 B4 B3 B2 B1 B0
D0
DSTi
11.7 µsec
F0o
Channel Time 0
D-Channel
Channel Time 2
B1-Channel
Channel Time 1
C-Channel
Figure 5 - DV Port - 80 kbit/s (Modes 0,4)
F0
C4
DSTo
D0 D1 D2 D3 D4 D5 D6 D7 C0 C1 C2 C3 C4 C5 C6 C7
B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0
D0
D0 D1 D2 D3 D4 D5 D6 D7 C0 C1 C2 C3 C4 C5 C6 C7
B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0
D0
DSTi
15.6 µsec
F0o
Channel Time 0
D-Channel
Channel Time 2
B1-Channel
Channel Time 1
C-Channel
Channel Time 3
B2-Channel
Figure 6 - DV Port - 160 kbit/s (Modes 0,4)
In DIGITAL NETWORK (DN) mode, upon entering the DNIC from the DV and CD ports, the B-channel data, Dchannel D0 (and D1 for 160 kbit/s), the HK bit of the C-channel (160 kbit/s only) and a SYNC bit are combined in a
serial format to be sent out on the line by the Transmit Interface (Figures 11, 12). The SYNC bit produces an
alternating 1-0 pattern each frame in order for the remote end to extract the frame alignment from the line. It is
possible for the remote end to lock on to a data bit pattern which simulates this alternating 1-0 pattern that is not the
true SYNC. To decrease the probability of this happening the DNIC may be programmed to put the data through a
prescrambler that scrambles the data according to a predetermined polynomial with respect to the SYNC bit. This
greatly decreases the probability that the SYNC pattern can be reproduced by any data on the line. In order for the
echo canceller to function correctly, a dedicated scrambler is used with a scrambling algorithm which is different for
the SLV and MAS modes. These algorithms are calculated in such a way as to provide orthogonality between the
near and far end data streams such that the correlation between the two signals is very low.
For any two DNICs on a link, one must be in SLV mode with the other in MAS mode. The scrambled data is
differentially encoded which serves to make the data on the line polarity-independent. It is then biphase encoded as
shown in Figure 10. See “Line Interface” section for more details on the encoding. Before leaving the DNIC the
differentially encoded biphase data is passed through a pulse-shaping bandpass transmit filter that filters out the
high and low frequency components and conditions the signal for transmission on the line.
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Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
F0
C4
CDSTo
C0 C 1 C2 C 3 C4 C5 C6 C7
D 0 D1 D 2 D3 D 4 D5 D 6 D7
C0
CDSTi
C0 C 1 C2 C 3 C4 C5 C6 C7
D 0 D1 D 2 D3 D 4 D5 D 6 D7
C0
F0o
3.9 µsec
62.5 µsec
125 µsec
Channel Time 0
Channel Time 16
Figure 7 - CD Port (Modes 2,6)
CLD
TCK
CDi
C6
C7
C0
C1
C2
C3
C4
C5
C6
C7
C0
C1
CDo
C6
C7
C0
C1
C2
C3
C4
C5
C6
C7
C0
C1
Figure 8 - CD Port (Modes 1,5)
The composite transmit and receive signal is received at LIN. On entering the DNIC this signal passes through a
Precanceller which is a summing amplifier and lowpass filter that partially cancels the near-end signal and provides
first order antialiasing for the received signal. Internal, partial cancellation of the near end signal may be disabled by
holding the Precan pin high. This mode simplifies the design of external line transceivers used for loop extension
applications. The Precan pin features an internal pull-down which allows this pin to be left unconnected in
applications where this function is not required. The resultant signal passes through a receive filter to bandlimit and
equalize it. At this point, the echo estimate from the echo canceller is subtracted from the precancelled received
signal. This difference signal is then input to the echo canceller as an error signal and also squared up by a
comparator and passed to the biphase receiver. Within the echo canceller, the sign of this error signal is
determined. Depending on the sign, the echo estimate is either incremented or decremented and this new estimate
is stored back in RAM.
The timebase in both SLV and MAS modes (generated internally in SLV mode and externally in MAS mode) is
phase-locked to the received data stream. This phase-locked clock operates the Biphase Decoder, Descrambler
and Deprescrambler in MAS mode and the entire chip in SLV mode. The Biphase Decoder decodes the received
encoded bit stream resulting in the original NRZ data which is passed onto the Descrambler and Deprescrambler
where the data is restored to its original content by performing the reverse polynomials. The SYNC bits are
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Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
extracted and the Receive Interface separates the channels and outputs them to the proper ports in the proper
channel times. The destination of the various channels is the same as that received on the input DV and CD ports.
The Transmit/Receive Timing and Control block generates all the clocks for the transmit and receive functions and
controls the entire chip according to the control register. In order that more than one DNIC may be connected to the
same DV and CD ports an F0o signal is generated which signals the next device in a daisy chain that its channel
times are now active. In this arrangement only the first DNIC in the chain receives the system F0 with the following
devices receiving its predecessor’s F0o.
In MOD mode, all the ports have a different format. The line port again operates at 80 or 160 kbit/s, however, there
is no synchronization overhead, only transparent data. The DV and CD ports carry serial data at 80 or 160 kbit/s
with the DV port transferring all the data for the line and the CD port carrying the C-channel only. In this mode the
transfer of data at both ports is synchronized to the TCK and RCK clocks for transmit and receive data, respectively.
The CLD signal goes low to indicate the start of the C-channel data on the CD port. It is used to load and latch the
input and output C-channel but has no relationship to the data on the DV port.
Operating Modes (MS0-2)
The logic levels present on the mode select pins MS0, MS1 and MS2 program the DNIC for different operating
modes and configure the DV and CD ports accordingly. Table 1 shows the modes corresponding to the state of
MS0-2. These pins select the DNIC to operate as a MASTER or SLAVE, in DUAL or SINGLE port operation, in
MODEM or DIGITAL NETWORK mode and the order of the C and D channels on the CD port. Table 2 provides a
description of each mode and Table 3 gives a pin configuration according to the mode selected for all pins that have
variable functions. These functions vary depending on whether it is in MAS or SLV, and whether DN or MOD mode
is used.
Mode Select Pins
Operating Mode
Mode
SLV
MAS
DUAL
SINGL
MO
D
MS2
MS1
MS0
0
0
0
0
E
0
0
1
1
E
E
0
1
0
2
E
E
E
0
1
1
3
E
E
E
1
0
0
4
E
1
0
1
5
E
E
1
1
0
6
E
E
E
1
1
1
7
E
E
E
D-C
E
E
E
E
E
DN
Table 1 - Mode Select Pins
E=Enabled
X=Not Applicable
Blanks are disabled
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Zarlink Semiconductor Inc.
X
E
E
C-D
E
X
E
E
E
E
E
E
X
E
ODE
E
X
E
E
E
MT9171/72
Mode
Data Sheet
Function
SLV
SLAVE - The chip timebase is extracted from the received line data and the external 10.24 MHz
crystal is phase locked to it to provide clocks for the entire device and are output for the external
system to synchronize to.
MAS
MASTER - The timebase is derived from the externally supplied data clocks and 10.24 MHz clock
which must be frequency locked. The transmit data is synchronized to the system timing with the
receive data recovered by a clock extracted from the receive data and resynchronized to the system
timing.
DUAL
DUAL PORT - Both the CD and DV ports are active with the CD port transferring the C&D channels
and the DV port transferring the B1& B2 channels.
SINGL
SINGLE PORT - The B1& B2, C and D channels are all transferred through the DV port. The CD
port is disabled and CDSTi should be pulled high.
MOD
MODEM - Baseband operation at 80 or 160 kbits/s. The line data is received and transmitted
through the DV port at the baud rate selected. The C-channel is transferred through the CD port
also at the baud rate and is synchronized to the CLD output.
DN
DIGITAL NETWORK - Intended for use in the digital network with the DV and CD ports operating at
2.048 Mbits/s and the line at 80 or 160 kbits/s configured according to the applicable ISDN
recommendation.
D-C
D BEFORE C-CHANNEL
C-D
ODE
- The D-channel is transferred before the C-channel following F0.
C BEFORE D-CHANNEL - The C-channel is transferred before the D-channel following F0.
OUTPUT DATA ENABLE - When mode 7 is selected, the DV and CD ports are put in high
impedance state. This is intended for power-up reset to avoid bus contention and possible damage
to the device during the initial random state in a daisy chain configuration of DNICs. In all the other
modes of operation DV and CD ports are enabled during the appropriate channel times.
Table 2 - Mode Definitions
F0o/RCK
F0/CLD
C4/TCK
Mode
#
Name
Input/Output
Name
Input/Output
Name
Input/Output
0
1
F0
CLD
Input
Output
F0o
RCK
Output
Output
C4
TCK
Input
Output
2
F0
Input
F0o
Output
C4
Input
3
F0
Input
F0o
Output
C4
Input
4
F0
Output
F0o
Output
C4
Output
5
CLD
Output
RCK
Output
TCK
Output
6
F0
Output
F0o
Output
C4
Output
7
F0
Input
F0o
Output
Table 3 - Pin Configurations
C4
Input
The overall mode of operation of the DNIC can be programmed to be either a baseband modem (MOD mode) or a
digital network transceiver (DN mode). As a baseband modem, transmit/receive data is passed transparently
through the device at 80 or 160 kbit/s by the DV port. The CD port transfers the C-channel and D-Channel also at
80 or 160 kbit/s.
In DN mode, both the DV and CD ports operate as ST-BUS streams at 2.048 Mbit/s. The DV port transfers data
over pins DSTi and DSTo while on the CD port, the CDSTi and CDSTo pins are used. The SINGL port option only
exists in DN mode.
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Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
In MOD mode, DUAL port operation must be used and the D, B1 and B2 channel designations no longer exist. The
selection of SLV or MAS will determine which of the DNICs is using the externally supplied clock and which is
phase locking to the data on the line. Due to jitter and end to end delay, one end must be the master to generate all
the timing for the link and the other must extract the timing from the receive data and synchronize itself to this timing
in order to recover the synchronous data. DUAL port mode allows the user to use two separate serial busses: the
DV port for PCM/data (B channels) and the CD port for control and signalling information (C and D channels). In the
SINGL port mode, all four channels are concatenated into one serial stream and input to the DNIC via the DV port.
The order of the C and D channels may be changed only in DN/DUAL mode. The DNIC may be configured to
transfer the D-channel in channel 0 and the C-channel in channel 16 or vice versa. One other feature exists; ODE,
where both the DV and CD ports are tristated in order that no devices are damaged due to excessive loading while
all DNICs are in a random state on power up in a daisy chain arrangement.
DV Port (DSTi/Di, DSTo/Do)
The DV port transfers data or PCM encoded voice to and from the line according to the particular mode selected by
the mode select pins. The modes affecting the configuration of the DV port are MOD or DN and DUAL or SINGL. In
DN mode the DV port operates as an ST-BUS at 2.048 Mbit/s with 32, 8 bit channels per frame as shown in Figure
9. In this mode the DV port channel configuration depends upon whether DUAL or SINGL port is selected. When
DUAL port mode is used, the C and D channels are passed through the CD port and the B1 and B2 channels are
passed through the DV port. At 80 kbit/s only one channel of the available 32 at the DV port is utilized, this being
channel 0 which carries the B1-channel. This is shown in Figure 3. At 160 kbit/s, two channels are used, these
being 0 and 16 carrying the B1 and B2 channels, respectively. This is shown in Figure 4. When SINGL port mode is
used, channels B1, B2, C and D are all passed via the DV port and the CD port is disabled. See CD port description
for an explanation of the C and D channels.
F0
125 µsec
ST-BUS
Channel
31
Channel
0
Channel
1
Channel
2
Most
Significant
Bit (First)
Bit 7
Channel
29
••••••••
Bit 6
Bit 5
Bit 4
Bit 3
Channel
30
Bit 2
Bit 1
Channel
31
Bit 0
Channel
0
Least
Significant
Bit (Last)
3.9 µsec
Figure 9 - ST-BUS Format
The D-channel is always passed during channel time 0 followed by the C and B1 channels in channel times 1 and
2, respectively for 80 kbit/s. See Figure 5. For 160 kbit/s the B2 channel is added and occupies channel time 3 of
the DV port. See Figure 6. For all of the various configurations the bit orders are shown by the respective diagram.
In MOD mode the DV and CD ports no longer operate at 2.048 Mbits/s but are continuous serial bit streams
operating at the bit rate selected of 80 or 160 kbit/s.
While in the MOD mode only DUAL port operation can be used.
In order for more than one DNIC to be connected to any one DV and CD port, making more efficient use of the
busses, the DSTo and CDSTo outputs are put into high impedance during the inactive channel times of the DNIC.
This allows additional DNICs to be cascaded onto the same DV and CD ports. When used in this way a signal
called F0o is used as an indication to the next DNIC in a daisy chain that its channel time is now active. Only the
first DNIC in the chain receives the system frame pulse and all others receive the F0o from its predecessor
in the chain. This allows up to 16 DNICs to be cascaded.
10
Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
CD Port (CDSTi/CDi, CDSTo/CDo)
The CD port is a serial bidirectional port used only in DUAL port mode. It is a means by which the DNIC receives its
control information for things such as setting the bit rate, enabling internal loopback tests, sending status
information back to the system and transferring low speed signalling data to and from the line.
The CD port is composed of the C and D-Channels. The C-channel is used for transferring control and status
information between the DNIC and the system. The D-channel is used for sending and receiving signalling
information and lower speed data between the line and the system. In DN/DUAL mode the DNIC receives a Cchannel on CDSTi while transmitting a C-channel on CDSTo. Fifteen channel times later (halfway through the
frame) a D-channel is received on CDSTi while a D-channel is transmitted on CDSTo. This is shown in Figure 7.
The order of the C and D bytes in DUAL port mode can be reversed by the mode select pins. See Table 1 for a
listing of the byte orientations.
The D-channel exists only in DN mode and may be used for transferring low speed data or signalling information
over the line at 8, 16 or 64 kbit/s (by using the DINB feature). The information passes transparently through the
DNIC and is transmitted to or received from the line at the bit rate selected in the Control Register.
If the bit rate is 80 kbit/s, only D0 is transmitted and received. At 160 kbit/s, D0 and D1 are transmitted and
received. When the DINB bit is set in the Control Register the entire D-channel is transmitted and received in the
B1-channel timeslot.
The C-channel is used for transferring control and status information between the DNIC and the system. The
Control and Diagnostics Registers are accessed through the C-channel. They contain information to control the
DNIC and carry out the diagnostics as well as the HK bit to be transmitted on the line as described in Tables 4 and
5. Bits 0 and 1 of the C-channel select between the Control and Diagnostics Register. If these bits are 0, 0 then the
C-channel information is written to the Control Register (Table 4). If they are 0, 1 the C-channel is written to the
Diagnostics Register (Table 5).
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
Reg Sel-1
Reg Sel-2
DRR
BRS
DINB
PSEN
ATTACK
TxHK
Default Mode Selection (Refer to Table 4a)
Bit
Name
Description
0
Reg Sel-1
Register Select-1. Must be set to ’0’ to select the Control Register.
1
Reg Sel-2
Register Select-2. Must be set to ’0’ to select the Control Register.
2
DRR
Diagnostics Register Reset. Writing a "0" to this bit will cause a diagnostics register reset
to occur coincident with the next frame pulse as in the MT8972A. When this bit is a logic
"1", the Diagnostics Register will not be reset.
3
BRS
Bit Rate Select. When set to ’0’ selects 80 kbit/s. When set to ’1’, selects 160 kbit/s.
4
DINB2
D-Channel in B Timeslot. When ’0’, the D-channel bits (D0 or D0 and D1) corresponding
to the selected bit rate (80 or 160 kbit/s) are transmitted during the normal D-channel bit
times. When set to ’1’, the entire D-channel (D0-D7) is transmitted during the B1-channel
timeslot on the line providing a 64 kbit/s D-channel link.
5
PSEN2
Prescrambler/Deprescrambler Enable. When set to ’1’, the data prescrambler and
deprescrambler are enabled. When set to ’0’, the data prescrambler and deprescrambler
are disabled.
11
Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
Reg Sel-1
Reg Sel-2
DRR
BRS
DINB
PSEN
ATTACK
TxHK
Default Mode Selection (Refer to Table 4a)
Bit
Name
6
ATTACK
7
TxHK2
Description
2
Convergence Speedup. When set to ’1’, the echo canceller will converge to the reflection
coefficient much faster. Used on power-up for fast convergence.1 When ’0’, the echo
canceller will require the normal amount of time to converge to a reflection coefficient.
Transmit Housekeeping. When set to ’0’, logic zero is transmitted over the line as
Housekeeping Bit. When set to ’1’, logic one is transmitted over the line as
Housekeeping Bit.
Table 4 - Control Register
Notes:
1. Suggested use of ATTACK:
-At 160 kbit/s full convergence requires 850 ms with ATTACK held high for the first 240 frames or 30 ms.
-At 80 kbit/s full convergence requires 1.75 s with ATTACK held high for the first 480 frames or 60 ms.
2. When bits 4-7 of the Control Register are all set to one, the DNIC operates in one of the default modes as defined in Table 4a,
depending upon the status of bit-3.
C-Channel
(Bit 0-7)
Internal Control
Register
Internal Diagnostic
Register
XXX01111
00000000
01000000
XXX11111
00010000
Description
Default Mode-13: Bit rate is 80 kbit/s. ATTACK,
PSEN, DINB, DRR and all diagnostics are disabled.
TxHK=0.
Default Mode-24 Bit rate is 160 kbit/s. ATTACK,
PSEN, DINB, DRR and all diagnostics are disabled.
TxHK=0.
Table 4a - Default Mode Selection
01000000
Notes:
3. Default Mode 1 can also be selected by tying CDSTi/CDi pin low when DNIC is operating in dual mode.
4. Default Mode 2 can also be selected by tying CDSTi/CDi pin high when DNIC is operating in dual mode.
bit 0
bit 1
Reg Sel-1
Reg Sel-2
bit 2
bit 3
Loopback
bit 4
bit 5
bit 6
bit 7
FUN
PSWAP
DLO
Not Used
Default Mode Selection
(Refer to Table 4a)
Bit
Name
Description
0
Reg Sel-1
Register Select-1. Must be set to ’0’ to select the Diagnostic Register.
1
Reg Sel-2
Register Select-2. Must be set to ’1’ to select the Diagnostic Register.
2,3
Loopback
Bit 2
0
0
1
1
Bit 3
0
1
0
1
All loopback testing functions disabled. Normal operation.
DSTi internally looped back into DSTo for system diagnostics.
LOUT is internally looped back into LIN for system diagnostics.2
DSTo is internally looped back into DSTi for end-to-end testing.3
12
Zarlink Semiconductor Inc.
MT9171/72
bit 0
bit 1
bit 2
Reg Sel-1
Reg Sel-2
bit 3
Loopback
Data Sheet
bit 4
bit 5
bit 6
bit 7
FUN
PSWAP
DLO
Not Used
Default Mode Selection
(Refer to Table 4a)
Bit
Name
1
Description
Force Unsync. When set to ’1’, the DNIC is forced out-of-sync to test the SYNC
recovery circuitry. When set to ’0’, the operation continues in synchronization.
4
FUN
5
PSWAP1
Polynomial Swap. When set to ’1’, the scrambling and descrambling polynomials
are interchanged (use for MAS mode only). When set to ’0’, the polynomials retain
their normal designations.
6
DLO1
Disable Line Out. When set to ’1’, the signal on LOUT is set to VBias. When set to ’0’,
LOUT pin functions normally.
7
Not Used
Must be set to ’0’ for normal operation.
Table 5 - Diagnostic Register
Notes:
1. When bits 4-7 of the Diagnostic Register are all set to one, the DNIC operates in one of the default modes as defined in Table 4a,
depending upon the status of bit-3.
2. Do not use LOUT to L IN loopback in DN/SLV mode.
3. Do not use DSTo to DSTi loopback in MOD/MAS mode.
The Diagnostics Register Reset bit (bit 2) of the Control Register determines the reset state of the Diagnostics
Register. If, on writing to the Control Register, this bit is set to logic “0”, the Diagnostics Register will be reset
coincident with the frame pulse. When this bit is logic “1”, the Diagnostics Register will not be reset. In order to use
the diagnostic features, the Diagnostics Register must be continuously written to. The output C-channel sends
status information from the Status Register to the system along with the received HK bit as shown in Table 6.
0
1
SYNC
2
CHQual
3
4
Rx HK
5
6
Future Functionality
7
ID
Status
Register
Name
0
SYNC
Synchronization - When set this bit indicates that synchronization to the received
line data sync pattern has been acquired. For DN mode only.
1-2
CHQual
Channel Quality - These bits provide an estimate of the receiver’s margin against
noise. The farther this 2 bit value is from 0 the better the SNR.
3
Rx HK
Housekeeping - This bit is the received housekeeping (HK) bit from the far end.
4-6
Future
Future Functionality. These bits return Logic 1 when read.
7
ID
Function
This bit provides a hardware identifier for the DNIC revision. The MT9171/72 will
return a logic “0” for this bit. (Logic “1” returned for MT8972A.)
Table 6 - Status Register
13
Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
In MOD mode, the CD port is no longer an ST-BUS but is a serial bit stream operating at the bit rate selected. It
continues to transfer the C-channel but the D-channel and the HK bit no longer exist. DUAL port operation must be
used in MOD mode. The C-channel is clocked in and out of the CD port by TCK and CLD with TCK defining the bits
and CLD the channel boundaries of the data stream as shown in Figure 8.
Line Port (LIN, LOUT)
The line interface is made up of LOUT and LIN with LOUT driving the transmit signal onto the line and LIN receiving the
composite transmit and receive signal from the line. The line code used in the DNIC is Biphase and is shown in
Figure 10. The scrambled NRZ data is differentially encoded meaning the previous differential encoded output is
XOR’d with the current data bit which produces the current output. This is then biphase encoded where transitions
occur midway through the bit cell with a negative going transition indicating a logic "0" and a positive going
transition indicating a logic "1".
There are some major reasons for using a biphase line code. The power density is concentrated in a spectral
region that minimizes dispersion and differential attenuation. This can shorten the line response and reduce the
intersymbol interference which are critical for adaptive echo cancellation. There are regular zero crossings halfway
through every bit cell or baud which allows simple clock extraction at the receiving end. There is no D.C. content in
the code so that phantom power feed may be applied to the line and simple transformer coupling may be used with
no effect on the data. It is bipolar, making data reception simple and providing a high signal to noise ratio. The
signal is then passed through a bandpass filter which conditions the signal for the line by limiting the spectral
content from 0.2fBaud to 1.6fBaud and on to a line driver where it is made available to be put onto the line biased at
VBias. The resulting transmit signal will have a distributed spectrum with a peak at 3/4fBaud. The transmit signal
(LOUT) may be disabled by holding the LOUT DIS pin high or by writing DLO (bit 6) of the Diagnostics Register to
logic “1”. When disabled, LOUT is forced to the VBias level. LOUT DIS has an internal pull-down to allow this pin to be
left not connected in applications where this function is not required. The receive signal is the above transmit signal
superimposed on the signal from the remote end and any reflections or delayed symbols of the near end signal.
The frame format of the transmit data on the line is shown in Figures 11 and 12 for the DN mode at 80 and 160
kbit/s. At 80 kbit/s a SYNC bit for frame recovery, one bit of the D-channel and the B1-channel are transmitted. At
160 kbit/s a SYNC bit, the HK bit, two bits of the D-channel and both B1 and B2 channels are transmitted.
If the DINB bit of the Control Register is set, the entire D-channel is transmitted during the B1-channel timeslot. In
MOD mode the SYNC, HK and D-channel bits are not transmitted or received but rather a continuous data stream
at 80 or 160 kbit/s is present. No frame recovery information is present on the line in MOD mode.
14
Zarlink Semiconductor Inc.
MT9171/72
Bits
Data
Bit 7
1
Data Sheet
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1
1
0
0
1
0
0
NRZ Data
Differential
Encoded
Differential
Encoded
Biphase
Transmit
Line Signal
VBias
Note: Last bit sent was a logic 0
Figure 10 - Data & Line Encoding
F0
LOUT
B17
SYNC
D0
B10
B11
B12
B13
B14
B15
B16
Figure 11 - Frame Format - 80 kbit/s (Modes 0, 2, 3, 4, 6)
15
Zarlink Semiconductor Inc.
B17
SYNC
MT9171/72
Data Sheet
F0
LOUT
SYNC
HK0
D1
D0
B10 B11 B12 B13 B14 B15 B16 B17 B20 B21 B22
B23
B24
B25 B26
B27
SYNC
Figure 12 - Frame Format - 160 kbit/s (Modes 0, 2, 3, 4, 6)
Applications
Typical connection diagrams are shown in Figures 13 and 14 for the DN mode as a MASTER and SLAVE,
respectively. LOUT is connected to the coupling transformer through a resistor R2 and capacitors C2 and C2’ to
match the line characteristic impedance. Suggested values of R2, C2 and C2’ for 80 and 160 kbit/s operation are
provided in Figures 13 and 14. Overvoltage protection is provided by R1, D1 and D2. C1 is present to properly bias
the received line signal for the LIN input. A 2:1 coupling transformer is used to couple to the line with a secondary
center tap for optional phantom power feed. Varistors have been shown for surge protection against such things as
lightning strikes.
If the scramblers power up with all zeros in them, they are not capable of randomizing all-zeros data sequence. This
increases the correlation between the transmit and receive data which may cause loss of convergence in the echo
canceller and high bit error rates.
In DN mode the insertion of the SYNC pattern will provide enough pseudo-random activity to maintain
convergence. In MOD mode the SYNC pattern is not inserted. For this reason, at least on ”1” must be fed into the
DNIC on power up to ensure that the scramblers will randomize any subsequent all-zeros sequence.
C2’ = 1.5 nF
DV Port ST-BUS
CD Port ST-BUS
Master Clocks
{
DSTi
{
CDSTi
CDSTo
{
F0
C4
DSTo
For 80 kbit/s: C2’ = 3.3 nF
+5V
MT9171/72
C2 = 22 nF
D1 = D2 = MUR405
LOUT
R2 = 390Ω
D2
R1 = 47Ω
LIN
2:1
Line Feed
Voltage
1.0 µF
MS0
Mode Select
Lines
+5 V
0.33 µF
0.33 µF
MS1
MS2
VRef
VBias
OSC1
OSC2
F0o
D.C. coupled,
Frequency locked
10.24 MHz clock.
Refer
to AC Electrical
NC
Characteristics
Clock Timing
C1 = 0.33 µF
DN Mode.
68 Volts
(Typ)
2.5 Joules
0.02 Watt
Note: Low leakage diodes (1 & 2) are required so
that the DC voltage at LIN ≈ VBias
To Next DNIC
Figure 13 - Typical Connection Diagram - MAS/DN Mode, 160 kbit/s
16
Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
C2’ = 1.5 nF
DV Port ST-BUS
{
C2 = 22 nF
DSTi
DSTo
CD Port ST-BUS
{
CDSTi
CDSTo
Master Clocks
{
F0
C4
For 80 kbit/s: C2’ = 3.3 nF
+5V
MT9171/72
D1 = D2 = MUR405
LOUT
R2 = 390 Ω
D2
2:1
R1 = 47 Ω
LIN
1.0 µF
MS0
Mode Select
Lines
+5 V
0.33 µF
0.33 µF
MS1
MS2
OSC1
VRef
OSC2
VBias
Supply
68 Volts
(Typ)
2.5 Joules
0.02 Watt
10.24 MHz XTAL
C3=33pF=C4
C1 = 0.33 µF
Note: Low leakage diodes (1 & 2) are required so
that the DC voltage at LIN ≈ VBias
Figure 14 - Typical Connection Diagram - SLV/DN Mode, 160 kbit/s
17
Zarlink Semiconductor Inc.
MT9171/72
Absolute Maximum Ratings**
Data Sheet
- Voltages are with respect to ground (VSS) unless otherwise stated.
Parameter
Symbol
Min.
Max.
Units
1
Supply Voltage
VDD
-0.3
7
V
2
Voltage on any pin (other than supply)
VMax
-0.3
VDD+0.3
V
3
Current on any pin (other than supply)
IMax
40
mA
4
Storage Temperature
TST
+150
°C
5
Package Power Dissipation (Derate 16mW/°C above 75°C)
PDiss
750
mW
-65
** Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied.
Recommended Operating Conditions†
- Voltages are with respect to ground (VSS) unless otherwise stated.
Characteristics
Sym.
Min.
Typ.*
Max.
Units
5.00
5.25
V
Test Conditions
1
Operating Supply Voltage
VDD
4.75
2
Operating Temperature
TOP
-40
+85
°C
3
Input High Voltage (except OSC1)
VIH
2.4
VDD
V
for 400 mV noise margin
4
Input Low Voltage (except OSC1)
VIL
0
0.4
V
for 400 mV noise margin
* Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
† Parameters over recommended temperature & power supply voltage ranges.
DC Electrical Characteristics†
- Voltages are with respect to ground (VSS) unless otherwise stated.
Characteristics
Sym.
Min.
Typ.*
Max.
Units
Test Conditions
1
Operating Supply Current
IDD
2
Output High Voltage (ex OSC2)
VOH
2.4
V
3
Output High Current
(except OSC2)
IOH
10
mA
Source current. VOH=2.4V
Output High Current - OSC2
IOH
10
µA
Source current VOH=3.5V
Output Low Voltage (ex OSC2)
VOL
V
IOL=5mA
Output Low Current
(except OSC2)
IOL
5
Output Low Current - OSC2
IOL
10
8
High Imped. Output Leakage
IOZ
9
Output Voltage
VO
4
5
6
7
10
O
U
T
P
U
T
S
(VRef)
(VBias)
10
mA
0.4
7.5
10
VBias-1.8
VDD/2
18
Zarlink Semiconductor Inc.
IOH=10mA
mA
Sink current. VOL=0.4V
µA
Sink current. VOL=1.5V
µA
VIN=VSS to VDD
V
V
MT9171/72
DC Electrical Characteristics†
Data Sheet
- Voltages are with respect to ground (VSS) unless otherwise stated.
Characteristics
Sym.
Min.
2.0
Typ.*
Max.
Units
11
Input High Voltage (ex OSC1)
VIH
12
Input Low Voltage (ex OSC1)
VIL
Input High Voltage (OSC1)
VIHo
Input Low Voltage (OSC1)
VILo
1.0
V
IIL
10
µA
13
14
15
16
I
N
P
U
T
S
Input Leakage Current
Input Pulldown Impedance
LOUT DIS and Precan
V
0.8
4.0
ZPD
Test Conditions
V
V
50
VIN=VSS to VDD
kΩ
20
µA
Input Leakage Current for
IIOSC
OSC1 Input
Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
17
*
† Parameters over recommended temperature & power supply voltage ranges.
AC Electrical Characteristics† - Voltages are with respect to ground (VSS) unless otherwise stated.
Characteristics
Sym.
1
Input Voltage
(LIN)
VIN
2
Input Impedance
(LIN)
ZIN
3
4
5a
5b
6
7
8
9
10
I
N
P
U
T
S
Min.
Typ.*
Max.
Units
5.0
Vpp
20
kΩ
Test Conditions
fBaud=160 kHz
Crystal/Clock Frequency
fC
Crystal/Clock Tolerance
TC
-100
0
+100
ppm
Crystal/Clock Duty Cycle1
DCC
40
50
60
%
Normal temp. & VDD
Crystal/Clock Duty Cycle1
DCC
45
50
55
%
Recommended at max./
min. temp. & VDD
CL
33
50
pF
From OSC1 & OSC2 to VSS.
Co
8
pF
RLout
500
100
Ω
kΩ
Crystal/Clock Loading
Output Capacitance
(LOUT)
O
U Load Resistance
(LOUT)
T
(VBias, VRef)
P
(LOUT)
U Load Capacitance
(V
,
T
Bias VRef)
S
Output Voltage
(LOUT)
10.24
CLout
MHz
20
pF
µF
Capacitance to VBias.
4.6
Vpp
RLout = 500Ω, CLout = 20pF
0.1
Vo
3.2
4.3
† Timing is over recommended temperature & power supply voltages.
* Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
1. Duty cycle is measured at V DD/2 volts.
.
19
Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
AC Electrical Characteristics† - Clock Timing - DN Mode (Figures 16 & 17)
Characteristics
Sym.
Min.
Typ.*
Max.
Units
1
C4 Clock Period
tC4P
244
ns
2
C4 Clock Width High or Low
tC4W
122
ns
3
Frame Pulse Setup Time
tF0S
50
ns
4
Frame Pulse Hold Time
tF0H
50
ns
5
Frame Pulse Width
tF0W
244
ns
6
10.24 MHz Clock Jitter (wrt C4)
JC
±15
ns
Test Conditions
In Master Mode - Note 1
Note 2
† Timing is over recommended temperature & power supply voltages.
* Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
Notes: 1)
When operating as a SLAVE the C4 clock has a 40% duty cycle.
2)
When operating in MAS/DN Mode, the C4 and Oscillator clocks must be externally frequency-locked (i.e.,
F C=2.5xf C4). The relative phase between these two clocks (Φ in Fig. 17) is not critical and may vary from
0 ns to tC4P. However, the relative jitter must be less than J C (see Figure 17).
F0
C4
ST-BUS
BIT CELLS
Channel 31
Bit 0
Channel 0
Bit 7
Channel 0
Bit 6
Figure 15 - C4 Clock & Frame Pulse Alignment for ST-BUS Streams
tC4W
tC4P
2.0V
C4
0.8V
tF0S
tF0H
tC4W
tF0W
2.0V
F0
0.8V
Figure 16 - C4 Clock & Frame Pulse Alignment for ST-BUS Streams in DN Mode
C4
2.0V
0.8V
Φ
JC
3.0V
OSC1
2.0V
Figure 17 - Frequency Locking for the C4 and OSC1 Clocks in MAS/DN Mode
20
Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
AC Electrical Characteristics† - Clock Timing - MOD Mode (Figure 18)
80 kbit/s
Characteristics
160 kbit/s
Sym.
Units
Min.
Typ.*
Max.
Min.
Typ.*
Max.
1 TCK/RCK Clock Period
tCP
12.5
6.25
ms
2 TCK/RCK Clock Width
tCW
6.25
3.125
ms
3 TCK/RCK Clock Transition
Time
tCT
20
20
ns
4 CLD to TCK Setup Time
tCLDS
3.125
1.56
ms
5 CLD to TCK Hold Time
tCLDH
3.125
1.56
ms
6 CLD Width Low
tCLDW
6.05
2.925
ms
7 CLD Period
tCLDP
8xtCP
8xtCP
ms
Test
Conditions
CL=40pF
† Timing is over recommended temperature & power supply voltage ranges.
* Typical figures are at 25°C, for design aid only: not guaranteed and not subject to production testing.
tCP
tCT
tCW
2.4V
RCK
0.4V
tCP
2.4V
TCK
0.4V
tCLDH
tCLDS
tCW
tCLDW
2.4V
CLD
Note 1:
Note 2:
0.4V
TCK and CLD are generated on chip and provide the data clocks for the CD port and the transmit section of the
DV port. RCK, also generated on chip, is extracted from the receive data and only clocks out the data at the Do output
and may be skewed with respect to TCK due to end-to-end delay.
At the slave end TCK is phase locked to RCK.
The rising edge of TCK will lead the rising edge of RCK by approximately 90o.
Figure 18 - RCK, TCK & CLD Timing For MOD Mode
21
Zarlink Semiconductor Inc.
tCT
MT9171/72
Data Sheet
AC Electrical Characteristics† - Data Timing - DN Mode (Figure 19)
Characteristics
Sym.
Min.
Typ.*
Max.
Units
Test Conditions
1
DSTi/CDSTi Data Setup Time
tRS
30
ns
2
DSTi/CDSTi Data Hold Time
tRH
50
ns
3a
DSTo/CDSTo Data Delay
tTD
120
ns
CL=40pF
3b
DSTo/CDSTo High Z to Data Delay
tZTD
140
ns
CL=40pF
† Timing is over recommended temperature & power supply voltage ranges.
Bit
Stream
Bit Cell
2.0V
C4
DSTi
CDSTi
0.8V
2.0V
0.8V
tTD
tZTD
DSTo
CDSTo
tTD
tRH
tRS
2.4V
0.4V
Figure 19 - Data Timing For DN Mode
AC Electrical Characteristics† - Data Timing - MOD Mode (Figure 20)
Characteristics
Sym.
80 kbit/s
Min.
160 kbit/s
Typ.*
Max. Min. Typ.*
Max.
Units
Test
Conditions
1
Di/CDi Data Setup Time
tDS
150
150
ns
2
Di/CDi Data Hold Time
tDH
4.5
2.5
µs
3
Do Data Delay Time
tRD
70
70
ns
CL=40pF
4
CDo Data Delay Time
tTD
70
70
ns
CL=40pF
† Timing is over recommended temperature & power supply voltage ranges.
* Typical figures are at 25°C, for design aid only: not guaranteed and not subject to production testing.
Performance Characteristics of the MT9171 DSIC
Characteristics
Sym.
Min.
Typ.*
Max.
Units
Test Conditions
0
30
25
dB
SNRŠ16.5dB
(300kHz
bandlimited noise)
1
Allowable Attenuation for Bit Error
Rate of 10-6 (Note 1)
Afb
2
Line Length at 80 kbit/s
-24 AWG
-26 AWG
L80
3.0
2.2
km
attenuation - 6.9 dB/km
attenuation - 10.0 dB/km
3
Line Length at 160 kbit/s -24 AWG
-26 AWG
L160
3.0
2.2
km
attenuation - 8.0 dB/km
attenuation - 11.5 dB/km
22
Zarlink Semiconductor Inc.
MT9171/72
Data Sheet
Performance Characteristics of the MT9172 DNIC
Characteristics
Sym.
Min.
Typ.*
Max.
Units
Test Conditions
0
40
33
dB
SNR≥16.5dB
(300 kHz
bandlimited noise)
1
Allowable Attenuation for Bit Error
Rate of 10-6 (Note 1)
Afb
2
Line Length at 80 kbit/s
-24 AWG
-26 AWG
L80
5.0
3.4
km
attenuation - 6.9 dB/km
attenuation - 10.0 dB/km
3
Line Length at 160 kbit/s -24 AWG
-26 AWG
L160
4.0
3.0
km
attenuation - 8.0 dB/km
attenuation - 11.5 dB/km
Note 1: Attenuation measured from Master LOUT to Slave LIN at 3/4baud frequency.
* Typical figures are at 25°C, for design aid only: not guaranteed and not subject to production testing.
Tx Bit
Stream
TCK
Bit Cell
2.4V
0.4V
tDS
Di
CDI
tDH
2.0V
0.8V
tTD
tTD
CDo
2.4V
0.4V
Rx Bit
Stream
Bit Cell
tRD
tRD
RCK
2.4V
Do
0.4V
Figure 20 - Data Timing for Master Modem Mode
23
Zarlink Semiconductor Inc.
MT9171/72
TCK
Data Sheet
2.4V
0.4V
tDS
tDH
¼ tCP
Di
CDI
2.0V
0.8V
tTD
tTD
CDo
2.4V
0.4V
RCK
2.4V
Do
0.4V
Figure 21 - Data Timing for Slave Modem Mode
24
Zarlink Semiconductor Inc.
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