78P2351

Single Channel

OC-3/ STM1-E/ E4 LIU

TARGET DATASHEET

APRIL 2003

DESCRIPTION

The 78P2351 is TDK's second generation LIU for
155 Mbit/s SDH/SONET (OC-3, STS-3, or STM-1)
and 140Mbit/s PDH (E4) applications. The device is
a single chip solution that includes an integrated
CDR in the transmit path for flexible NRZ to CMI
conversion. The device can interface to 75

coaxial

cable using CMI coding or directly to a fiber optics
module using NRZ coding. The 78P2351 is
compliant with all respective ANSI, ITU-T, and
Telcordia standards for jitter tolerance, generation,
and transfer.

APPLICATIONS

Central Office Interconnects

DSLAMs

Add Drop Multiplexers (ADMs)

PDH/SDH test equipment

FEATURES

G.703 compliant line interface for 139.264 Mbps
or 155.52 Mbps CMI-coded coax transmission.

LVPECL compatible line interface for 155.52
Mbps NRZ-coded fiber applications.

Integrated adaptive CMI equalizer and CDR in
receive path.

Serial, LVPECL-compatible system interface
with integrated CDR in transmit path for NRZ to
CMI conversion.

4-bit parallel CMOS system interface with
master/slave Tx clock modes.

Configurable via HW control pins or 4-wire µP
interface

Operates from a single reference clock input.

Compliant with ANSI T1.105.03-1994; ITU-T
G.751, G.813, G.823, G.825, G.958; and
Telcordia GR-253-CORE for jitter performance.

Provides Loss of Lock (LOL), CMI Line Code
Violation (LCV), and G.775 compliant Loss of
Signal (LOS) detection.

Receive and Transmit Monitor Modes

Operates from a single 3.3V supply

100-pin TQFP (JEDEC LQFP) package

BLOCK DIAGRAM

Rx CDR

Adaptive

Eq.

CMI

Decoder

RXP/N

SODP/N

SOCKP/N

G.775

LOS

Detect

PO[3:0]D

POCK

CMI-LCV

Detect

PTOCK

PI[3:0]D

PICK

SICKP/N

SIDP/N

FIFO

Tx CDR

Lock Detect

CMI

Encoder

ECLP/N

Lock Detect

TXCKP/N

CMIP/N

CMI2P/N

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

TABLE OF CONTENTS

FUNCTIONAL DESCRIPTION

MODE SELECTION

REFERENCE CLOCK

RECEIVER OPERATION

Receiver Monitor Mode

Loss of Signal / Loss of Lock

TRANSMITTER OPERATION

Serial Modes

Parallel Modes

Transmit Driver

Transmit Monitor Mode

Clock Synthesizer

POWER-DOWN FUNCTION

LOOPBACK MODES

POWER-ON RESET

SERIAL CONTROL INTERFACE

PROGRAMMABLE INTERRUPTS

REGISTER DESCRIPTION

REGISTER ADDRESSING

REGISTER TABLE

LEGEND

GLOBAL REGISTERS

ADDRESS 0-0: MASTER CONTROL REGISTER

ADDRESS 0-1: INTERRUPT CONTROL REGISTER

ADDRESS 0-2: I/O CONTROL REGISTER

PORT-SPECIFIC REGISTERS 11

ADDRESS 1-0: MODE CONTROL REGISTER

ADDRESS 1-1: SIGNAL CONTROL REGISTER

ADDRESS 1-2: ADVANCED CONTROL REGISTER 1

ADDRESS 1-3: ADVANCED CONTROL REGISTER 2

ADDRESS 1-4: MODE CONTROL REGISTER 2

ADDRESS 1-5: STATUS MONITOR REGISTER

PIN DESCRIPTION

LEGEND

TRANSMITTER PINS

RECEIVER PINS

REFERENCE AND STATUS PINS

CONTROL PINS

SERIAL-PORT PINS

POWER AND GROUND PINS

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

TABLE OF CONTENTS

(continued)

ELECTRICAL SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

RECOMMENDED OPERATING CONDITIONS

DC CHARACTERISTICS

ANALOG PINS CHARACTERISTICS

DIGITAL I/O CHARACTERISTICS

Pins of type CI, CIU, CID 19
Pins of type CIS

Pins of type CO and COZ 19
Pins of type PO

SERIAL-PORT TIMING CHARACTERISTICS

TRANSMITTER TIMING CHARACTERISTICS

TIMING DIAGRAM: Transmitter Waveforms

REFERENCE CLOCK CHARACTERISTICS

RECEIVER TIMING CHARACTERISTICS

TIMING DIAGRAM: Receive Waveforms

TRANSMITTER SPECIFICATIONS FOR CMI INTERFACE

TRANSMITTER OUTPUT JITTER

RECEIVER (Transformer-coupled)

RECEIVER SPECIFICATIONS FOR CMI INTERFACE

RECEIVER JITTER TOLERANCE

RECEIVER JITTER TRANSFER FUNCTION

CMI Mode Loss of Signal Condition

APPLICATION INFORMATION

EXTERNAL COMPONENTS

TRANSFORMER SPECIFICATIONS

RECOMMENDED LVPECL TERMINATIONS

MECHANICAL SPECIFICATIONS

PACKAGE INFORMATION

Revision History

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

FUNCTIONAL DESCRIPTION

The 78P2351 contains all the necessary transmit
and receive circuitry for connection between
139.264Mbit/s and 155.52Mbit/s signals and the
digital universe.
The chip is controllable through pins or serial port
register settings. In hardware mode (pin control) the
SPSL pin must be low. In software mode (SPSL pin
high), control pins are disabled and the 78P2351
must be configured via the 4-wire serial port.

MODE SELECTION

The SDO_E4 pin or E4 register bit determines which
rate the device operates in according to the table
below. This control combined with CKSL also
selects the global reference frequency.

Rate

SDO_E4 pin

E4 bit

E4 High

STM-1, STS-3, OC-3

Low

The SEN_CMI pin or CMI register bit selects one of
two media for reception and transmission: coaxial
cable in CMI mode or optical fiber in ECL (NRZ)
mode.

Media (coding)

SEN_CMI pin

CMI bit

75 ohm Coax (CMI)

High

Fiber (NRZ)

Low

The SDI_PAR pin or PAR register bit selects the
interface to the framer to be four bit parallel or serial.
For each interface there are different clocking
schemes for the transmitter. These modes and
their controls are described in the TRANSMITTER
OPERATION section.

REFERENCE CLOCK

The 78P2351 requires a reference clock supplied to
the CKREFP/N pins. For reference frequencies of
77.76MHz or lower, the device accepts a single
ended CMOS input at CKREFP. For reference
frequencies of 139.264/155.52MHz, the device
accepts a differential clock input at CKREFP/N. The
frequency of this reference input is selected by the
rate selection and the CKSL control pin or register
bit.

Reference Frequency

CKSL pin

SDO_E4 low

SDO_E4 high

Low 19.44MHz

17.408MHz

Float 77.76MHz

N/A

High 155.52MHz

139.264MHz

CKSL[1:0] bits

E4 bit = 0

E4 bit = 1

0 0

19.44MHz

17.408MHz

1 0

77.76MHz

N/A

1 1

155.52MHz

139.264MHz

RECEIVER OPERATION

The receiver accepts serial data, at 155.52Mbit/s or
139.264Mbit/s from the RXP/N inputs. In CMI mode,
the CMI-coded inputs come from a coaxial cable that
is transformer-coupled to the chip. In ECL (NRZ)
mode, the input pins receive NRZ LVPECL level
signals from an O/E converter.
The CMI signal first enters an AGC, which has a
selectable gain range setting. When Receiver
Monitor Mode is enabled, the AGC can compensate
for a monitor signal with 16 to 20 dB of flat loss. The
signal then enters a high performance adaptive
equalizer designed to overcome inter-symbol
interference caused by long cable. The variable
gain differential amplifier automatically controls the
gain to maintain a constant voltage level output
regardless of the input voltage level. In ECL (NRZ)
mode, the input signals bypass the adaptive
equalizer.
The outputs of the data comparators are connected
to the clock recovery circuits. The clock recovery
system employs a digital PLL, which uses a
reference frequency derived from the clock applied
to the CKREFP/N pins.
After the clock and data have been recovered, the
data is converted to binary by the CMI to binary
decoder. The

CMI Line Code Violation (LCV

)

detector will flag code errors while the decoder
continues to function normally. The three conditions
that will flag a LCV are:

`0' has a falling transition mid-bit instead of a
rising transition

A high `1' is recovered when it should have
been a low `1'

A low `1' is recovered when it should have
been a high `1'

In serial mode, the clock and data are transmitted
through the LVPECL drivers. In parallel mode, the
data is converted into four bit parallel segments
before being transmitted through the CMOS drivers.

Receiver Monitor Mode

The SCK_MON pin or MON register bit puts the
receiver in monitor mode and adds 20dB of flat gain
to the receive signal before equalization. Receiver
Monitor Mode is available in CMI mode only.

Loss of Signal / Loss of Lock

The 78P2351 includes standards compliant Loss of
Signal (LOS) and Loss of Lock (LOL) indicators for
the receive signal. During LOS conditions, the
receive data outputs are squelched while the receive
clock outputs a line rate clock generated from the
reference clock input. The LOS indicator is intended
for electrical CMI interfaces only.

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

TRANSMITTER OPERATION

The transmitter section generates an analog signal
for transmission through either a transformer onto
the coaxial cable or directly to a fiber optics module.
The 78P2351 provides a flexible system interface for
compatibility with most off-the-shelf framers and
custom ASICs. The device supports a 4-bit parallel
interface in either slave or master clocking modes
and a number of serial NRZ modes.

Serial Modes

Figure 1

, serial NRZ data is input to the 78P2351

on the SIDP/N pins at LVPECL levels. The data is
latched in on the rising edge of SICKP/N. A clock
decoupling FIFO is provided to decouple the on chip
and off chip clocks. The SICKP/N clock provided by
the framer/mapper IC should be source synchronous
with the internal reference transmit clock if the FIFO
is to be used. Since both clocks go through different
delay paths, it is inevitable that the phase
relationship between the two clocks can vary in a
bounded manner due to the fact that the absolute
delays in the two paths can vary over time. The
FIFO is designed to allow long-term clock phase drift
not exceeding +/- 25.6ns to be handled without
transmit error. If the clock wander exceeds the
specified limits, the FIFO will over or under flow, and
the FERR register signal will be asserted. The FIFO
is then automatically re-centered. This signal can be
used to trigger an interrupt. This interrupt event is
cleared when an FRST pulse is applied, and the
FIFO is re-centered.
If no serial transmit clock is available, as in

Figure 2

the 78P2351 will recover a clock from the serial NRZ
data input and pass the data through the FIFO. In
this mode, the NRZ data should be source
synchronous with the reference clock applied at
CKREFP/N. The transmitter also includes a Loss of
Lock indicator (TXLOL) which can be used to trigger
and interrupt. Note that the FIFO is automatically re-
centered when the TXLOL register bit transitions
from high to low.

Figure 3

represents the condition where no serial

transmit clock is available and the data is not source
synchronous to the reference clock input. In this
mode, the 78P2351 will recover a clock from the
serial plesiochronous data and bypass the FIFO.

Each of the described transmit serial modes can be
configured in HW mode and SW mode as shown in
the table below:

HW Control Pins SW Control Bits

Serial Mode

SDI_PAR CKMODE PAR

SMOD[1:0]

Synchronous
clock + data
(CDR bypass)

Low Low 0 0

Synchronous
data

Low Floating

0 1

Plesiochronous
data
(FIFO bypass)

Low High 0 0

TDK

78P2351

Framer/

Mapper

NRZ

140 / 155 MHz

Reference

Clock

SODP/N

SOCKP/N

SIDP/N

CKREFP/N

RXP/N

CMIP/N

XFMR

CMI

Coax

140 / 155 MHz

SICKP/N

Figure 1: Synchronous; clock and data available

(Tx CDR bypassed, FIFO enabled)

TDK

78P2351

Framer/

Mapper

NRZ

140 / 155 MHz

Reference

Clock

SODP/N

SOCKP/N

SIDP/N

CKREFP/N

RXP/N

CMIP/N

XFMR

CMI

Coax

Figure 2: Synchronous; data only

(Tx CDR enabled, FIFO enabled)

TDK

78P2351

Framer/

Mapper

NRZ

140 / 155 MHz

Reference

Clock

Reference

Clock

SODP/N

SOCKP/N

SIDP/N

CKREFP/N

RXP/N

CMIP/N

XFMR

CMI

Coax

Figure 3: Plesiochronous; data only

(Tx CDR enabled, FIFO bypassed)

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

Parallel Modes

In parallel modes, 4-bit CMOS data segments are
input to the chip with a 38.88MHz clock. These
inputs are passed to the 4x8 decoupling FIFO and
then to a serializer for transmission. For maximum
compatibility, the 78P2351 can operate in both slave
and master clock modes as shown in Figures 4, 5
respectively..

HW Control Pins

SW Control Bits

Parallel
Mode

SDI_PAR CKMODE

PAR

PMODE

Slave

High Low/Float

Master

High High

4-bit CMOS TTL

TDK

78P2351

Framer/
Mapper

Reference

Clock

CKREFP/N

RXP/N

CMIP/N

XFMR

CMI

Coax

PO[3:0]D

POCK

PIxCK

PI[3:0]D

34/39 MHz

Figure 4: Slave Parallel Mode

4-bit CMOS TTL

TDK

78P2351

Framer/

Mapper

Reference

Clock

CKREFP/N

RXP/N

CMIP/N

XFMR

CMI

Coax

PO[3:0]D

POCK

PTOCK

PI[3:0]D

34/39 MHz

Figure 5: Master Parallel Mode

Transmit Driver

When the CMI pin is high, the chip is in CMI mode
and a 75

coaxial cable is used as the transmission

medium. In this mode, the CMIP/N pins connect the
chip to the coaxial cable through a transformer and
termination resistors. In CMI mode, the transmitter
shapes the transmit pulses to meet the appropriate
template. Advanced peaking and amplitude controls
are also available in both HW and SW modes to
accommodate for less than ideal board conditions
When the CMI pin is low, the chip is in ECL (NRZ)
mode. The output data signal from the ECLP/N pins
have LVPECL levels and interface directly to a fiber
module. The CMI driver, encoder and decoder are
disabled in ECL (NRZ) mode.

A 2x line rate clock is also available at the TXCKP/N
pins for downstream synchronization or interfacing
to equipment lacking integrated clock recovery.

Transmit Monitor Mode

An optional redundant transmit output is available in
CMI mode for transmit monitoring. These outputs
(CMI2P/N) are activated when the RCSL pin or
RCSL register bit is activated.

TDK

78P2351

RXP/N

CMIP/N

XFMR

CMI

Coax

CMI2P/N

XFMR

CMI

Coax

Figure 6: Transmit Monitor Output

Clock Synthesizer

The transmitter clock synthesizer is a low-jitter PLL
that generates a 311.04MHz (278.528MHz) clock for
the CMI encoder. A synthesized line rate reference
clock is also used in both the receive and transmit
sides.

POWER-DOWN FUNCTION

Power-down control is provided to allow the
78P2351 to be shut off. Transmit and receive
power-down can be set independently through SW
control. Global power-down is achieved by
powering down both the transmitter and receiver.
Note the serial interface and Configuration Registers
are not affected by power-down.
In HW mode, the transmitter can be powered down
using the TXPD control pin.

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

LOOPBACK MODES

In SW mode, LLBK and RLBK bits are provided to
activate the local and remote loopback modes
respectively. In HW mode, the LPBK pin can be
used to activate local and remote loopback modes
as shown below.

LPBK pin Loopback Mode

Low Normal

operation

Float

Remote (digital) Loopback:
Recovered receive clock and data
looped back to transmitter

High

Local (analog) Loopback:
Transmit clock and data looped back to
receiver

Rx CDR

Adaptive

Eq.

CMI

Decoder

RXP/N

SODP/N

SOCKP/N

G.775

LOS

Detect

PO[3:0]D

POCK

CMI-LCV

Detect

PTOCK

PI[3:0]D

PICK

SICKP/N

SIDP/N

FIFO

Tx CDR

Lock Detect

CMI

Encoder

ECLP/N

Lock Detect

TXCKP/N

CMIP/N

CMI2P/N

Figure 7: Local (Analog) Loopback

Rx CDR

Adaptive

Eq.

CMI

Decoder

RXP/N

SODP/N

SOCKP/N

G.775

LOS

Detect

PO[3:0]D

POCK

CMI-LCV

Detect

PTOCK

PI[3:0]D

PICK

SICKP/N

SIDP/N

FIFO

Tx CDR

Lock Detect

CMI

Encoder

ECLP/N

Lock Detect

TXCKP/N

CMIP/N

CMI2P/N

Figure 8: Remote (Digital) Loopback

POWER-ON RESET

Power-On Reset (POR) function is provided on chip.
Upon initial power-up, a reset pulse is internally
generated. This resets all registers to their default
values as well as all state machines within the
transceiver to known initial values. The reset signal
is also brought out to the

POR pin. The POR pin is

a special function pin that allows for the following:

Override the internal

POR signal by driving in

an external

POR signal;

Use the

POR signal to drive other IC's power-

on reset;

Add external capacitor to slow down the
release of power-on reset (approximately 8

per nF added).

The internal resistance of the

POR pin is

approximately 5k

SERIAL CONTROL INTERFACE

The serial port controlled register allows a generic
controller to interface with the 78P2351. It is used
for mode settings, diagnostics and test, retrieval of
status and performance information, and for on-chip
trimming. The SPSL pin must be high in order to
use the serial port.
The serial interface consists of four pins: Serial Port
Enable (SEN_CMI), Serial Clock (SCK_MON), Serial
Data In (SDI_PAR), and Serial Data Out (SDO_E4).
The SEN_CMI pin initiates the read and write
operations. It can also be used to select a particular
device allowing SCK_MON, SDI_PAR and SDO_E4
to be bussed together. SCK_MON is the clock input
that times the data on SDI_PAR and SDO_E4. Data
on SDI_PAR is latched in on the rising-edge of
SCK_MON, and data on SDO_E4 is clocked out
using the falling edge of SCK_MON.
SDI_PAR is used to insert mode, address, and
register data into the chip. Address and Data
information are input least significant bit (LSB) first.
The mode and address bit assignment and register
table are shown in the following section.
SDO_E4 is a tristate capable output. It is used to
output register data during a read operation.

SDO_E4 output is normally high impedance, and is
enabled only during the duration when register data
is being clocked out. Read data is clocked out least
significant bit (LSB) first.
If SDI_PAR coming out of the micro-controller chip is
also tristate capable, SDI_PAR and SDO_E4 can be
connected together to simplify connections.
The maximum clock frequency for register access is
20MHz.

PROGRAMMABLE INTERRUPTS

In addition to the receiver LOS and LOL status pins,
the 78P2351 provides a programmable interrupt for
both the transmitter and receiver. In HW control
mode, the default functions of each interrupt is as
follows:

INTTX = Transmit Loss of Lock (TXLOL) or
FIFO error (FERR)

INTRX = CMI Line Code Violation
(CMIERR)

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

REGISTER DESCRIPTION

REGISTER ADDRESSING

Address Bits

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Port

Address Sub-Address

Read/

Write

Assignment

PA[3] PA[2] PA[1] PA[0] SA[2] SA[1] SA[0] R/W*

REGISTER TABLE

a) PA[3:0] = 0 : Global Registers

Sub

Addr

Reg.

Name

Description

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0 MSCR

(R/W)

Master Control

<0>

-- PAR

<0>

CKSL[1]

<X>

CKSL[0]

<X>

-- --

SRST

<0>

1 INTC

(R/W)

Interrupt Control

INPOL

<0>

-- MCERR

<1>

MRLOS

<0>

MRLOL

<0>

MTLOL

<1>

MFERR

<1>

2 IOCR

(R/W)

I/O

Control

-- -- -- -- -- -- --

RCSL

<0>

b) PA[3:0] = 1 : Port-Specific Registers

Sub

Addr

Reg.

Name

Description

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0 MDCR

(R/W)

Mode Control

PDTX

<0>

PDRX

<0>

PMODE

<X>

SMOD[1]

<X>

SMOD[0]

<X>

MON

<0>

-- --

1 SGCR

(R/W)

Signal

Control -- -- --

RLBK

<0>

LLBK

<0>

RCLKP

<0>

TCLKP

<0>

FRST

<0>

2 ACR1

(R/W)

Advanced
Control 1

-- -- -- --

TPK

<0>

ACR2
(R/W)

Advanced
Control 2

-- -- -- -- --

BST[1]

<0>

BST[0]

<0>

4 MCR2

(R/W)

Mode Control 2

CMI

<1>

-- -- -- -- -- -- --

5 STAT

(R/C)

Status Monitor

CMIERR

<X>

RXLOS

<X>

RXLOL

<X>

-- TXLOL

<X>

FERR

<X>

6-7

Reserved

-- -- -- -- -- -- -- --

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

REGISTER DESCRIPTION

(continued)

LEGEND

TYPE DESCRIPTION

R/O

Read only

R/W

Read or Write

R/C Read

and

Clear

GLOBAL REGISTERS
ADDRESS 0-0: MASTER CONTROL REGISTER

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7 E4

R/W 0

Line Rate Selection:
Selects the line rate of all channels as well as the input clock frequency at the
CKREFP/N pins.
0: OC-3, STS-3, STM-1 (155.52MHz)
1: E4 (139.264MHz)

6 -- R/W 0

Unused

5 PAR R/W 0

Serial/Parallel Selection:
Selects the interface to the framer.
0: Serial
1: Parallel

4:3

CKSL

[1:0]

R/W X

Reference Clock Frequency Selection:
Selects the reference clock frequency input at CKREFP/N pins. Secondary
values correspond to E4 frequencies. Default values depend on the pin
selection upon reset.
11: 155.52MHz / 139.264MHz
10: 77.76MHz / NA
00: 19.44MHz / 17.408MHz

2:1 -- R/W 0 Unused

0 SRST R/W 0

Register Soft-Reset:
When this bit is set, all registers are reset to their default values. This register
bit is self-clearing.

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

REGISTER DESCRIPTION

(continued)

ADDRESS 0-1: INTERRUPT CONTROL REGISTER

This register selects the events that would cause the interrupt pins to be activated. User may set as many bits as
required.

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7 INPOL R/W 0

Interrupt Pin Polarity Selection:
0 : Interrupt output is active-low
1 : Interrupt output is active-high

6 -- R/W 0

Reserved

5 MCERR R/W 1

Receive CMI Code Error Mask (active low):
Gates the respective RXCER register bit to the

INTRX interrupt pin.

0: Mask
1: Pass

4 MRLOS R/W 0

Receive Loss of Signal Error Mask (active low):
Gates the respective RXLOS register bit to the

INTRX interrupt pin.

0: Mask
1: Pass

3 MRLOL R/W 0

Receive Loss of Lock Error Mask (active low):
Gates the respective RXLOL register bit to the

INTRX interrupt pin.

0: Mask
1: Pass

2 -- R/W 0

Unused

1 MTLOL R/W 1

TXLOL Error Mask (active low):
Gates the TXLOL register bit to the

INTTX interrupt pin.

0: Mask
1: Pass

0 MFERR R/W 1

FIERR Error Mask (active low):
Gates the respective FIERR register bit to the

INTTX interrupt pin.

0: Mask
1: Pass

ADDRESS 0-2: I/O CONTROL REGISTER

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7:1 -- R/W 0 Unused

0 RCSL R/W 0

Redundant Channel Enable:
Enables transmit monitor outputs at CMI2P/N pins.
0: Disable
1: Enable

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

REGISTER DESCRIPTION

(continued)

PORT-SPECIFIC REGISTERS

For PA[3:0] = 1 only. Accessing a register with port address greater than 1 constitutes an invalid command, and
the read/write operation will be ignored.

ADDRESS 1-0: MODE CONTROL REGISTER

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7 PDTX R/W 0

Transmitter Power-Down:
0 : Normal Operation
1 : Power-Down

6 PDRX R/W 0

Receiver Power-Down:
0 : Normal Operation
1 : Power-Down

5 PMODE R/W X

Parallel Mode Interface Selection:
When PAR=1 (Master Control Regsiter: bit 5), PMODE selects the source
of the transmit parallel input clock, either taken from the framer externally
or generated internally.
0: Parallel clock is taken as an input to the transmitter
1: Parallel clock is given as an output from the transmitter

4 SMOD[1] R/W

3 SMOD[0] R/W

Serial Mode Interface Selection:
When PAR=0 (Master Control Regsiter: bit 5), SMOD[1:0] configures the
transmitter's system interface.
SMOD[1] SMOD[0]
0 0 Synchronous clock and data are passed through a
FIFO. The CDR is bypassed.
1 0 Synchronous data is passed through the CDR and
then through the FIFO.
0 1 Plesiochronous data is passed through the CDR to
recover a clock, but the FIFO is bypassed because
the data is not synchronous with the reference clock.
1 1 Loop Timing Mode Enable: The recovered receive
clock is used as the reference for the transmit section.
The transmit data is passed through the CDR, but the
FIFO is bypassed.

2 MON R/W 0

Receive Monitor Mode Enable:
0: Normal Operation
1: When Adds 20dB of flat gain to the receive signal before equalization.
NOTE: Monitor mode is only available in CMI mode.

1 -- R/W 0

Reserved

0 -- R/W 1

Reserved

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

REGISTER DESCRIPTION

(continued)

ADDRESS 1-1: SIGNAL CONTROL REGISTER

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7:5 -- R/W 0 Reserved

4 RLBK R/W 0

3 LLBK R/W 0

Loopback Selection:
RLBK LLBK
0 0 Normal operation
1 0 Remote Loopback Enable: Recovered receive data
and clock are looped back to the transmitter for
retransmission. Valid for both parallel and serial
modes.
0 1 Local Loopback Enable: The serial transmit data is
looped back and used as the input to the receiver.

2 RCLKP R/W 0

Receive Clock Inversion Select:
This bit will invert the receive output clock.
0: Normal
1: Invert

1 TCLKP R/W 0

Transmit Clock Inversion Select:
This bit will invert the transmit input system clock.
0: Normal
1: Invert

0 FRST R/W 0

FIFO Reset:
0: Normal operation
1: Reset FIFO pointers to default locations.
NOTE: Transmit monitor port will also be affected by FRST

ADDRESS 1-2: ADVANCED CONTROL REGISTER 1

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7:2 -- R/W 0 Reserved

1 TPK R/W 0 Transmit Driver Peaking Enable:

TBD

0 DU R/W 0 Transmit Driver Reverse Peaking Enable:

TBD

ADDRESS 1-3: ADVANCED CONTROL REGISTER 2

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7:3 ---- R/W

10101

Reserved

2:1 BST[1:0] R/W 00 Transmit Driver Amplitude Boost:

TBD

0 ---- R/W 0

Reserved

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

REGISTER DESCRIPTION

(continued)

ADDRESS 1-4: MODE CONTROL REGISTER 2

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7 CMI R/W 1

Line Interface Mode Selection:
0: Optical (LVPECL)
1: Coaxial cable (CMI encoded)

6:0 -- R/W 0

Reserved

ADDRESS 1-5: STATUS MONITOR REGISTER

BIT

NAME

TYPE

DFLT

VALUE

DESCRIPTION

7 -- R/C

Unused

6 -- R/C

Reserved

5 CMIERR R/C X

Receive CMI Coding Error Indication:
This bit is set when the recovered receive CMI data is incorrectly coded.
0: Normal operation
1: CMI code error detected

4 RXLOS R/C X

Loss of Signal Indication:
0: Normal operation
1: Loss of signal condition detected
NOTE: RXLOS is intended for CMI mode only.

3 RXLOL R/C X

Receive Loss of Lock Indication:
0: Normal operation
1: Recovered receive clock frequency differs from the reference by more
than +/- 1000ppm.

2 -- R/C

Unused

1 TXLOL R/C X

Transmit Loss of Lock Indication:
0: Normal operation
1: Transmit CDR unlocked

0 FERR R/C X

Transmit FIFO Error Indication:
This bit is set whenever the internal FERR signal is asserted, indicating
that the FIFO is operating at its depth limit. It is reset to 0 when the
FRST pin is asserted.
0: Normal operation
1: Transmit FIFO phase error

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

PIN DESCRIPTION

LEGEND

TYPE

DESCRIPTION

TYPE

DESCRIPTION

Analog Pin

(Tie unused pins to ground)

LVPECL-Compatible Differential Output

(Tie unused pins to supply)

CIT

3-State CMOS Digital Input

CMOS Digital Output

(Leave unused pins floating)

CMOS Digital Input

(Tie unused pins to ground)

COZ

CMOS Tristate Digital Output

(Leave unused pins floating)

CIU

CMOS Digital Input w/ Pull-up

LVPECL-Compatible Differential Input

(Tie unused pins to ground)

CID

CMOS Digital Input w/ Pull-down

Supply

CIS

CMOS Schmitt Trigger Input

(Tie unused pins to ground)

G Ground

TRANSMITTER PINS

NAME

PIN

TYPE DESCRIPTION

PI0D
PI1D
PI2D
PI3D

24
25
26
27

Transmit Data Parallel Input:
The four bit CMOS parallel inputs are latched in on the rising edge of the
transmit parallel input clock. MSB of the data is transmitted first.

PICK

23 CI

Transmit Parallel Clock Input:
A 38.88MHz CMOS clock input that should be source synchronous with the
reference clock supplied at the CKREFP/N pins.

PTOCK

28 CO

Transmit Parallel Clock Output:
A 38.88MHz CMOS clock output that is intended to latch in synchronous
parallel data.

SIDP
SIDN

8
9

Transmit Serial Data Input:
This differential input is clocked in on the rising edge of the transmit serial
input clock. If source synchronous with the reference clock, this data can be
input to a FIFO, otherwise the clock and data can be transmitted directly. A
CDR can be multiplexed in to the transmit path if no serial clock is available.

SICKP
SICKN

5
6

Transmit Serial Clock Input:
A 155.52MHz synchronous differential input clock used to clock in the serial
data

CMIP
CMIN

93
94

Transmit Serial CMI Data Output:
A CMI encoded data signal conforming to the relevant pulse templates

CMI2P

CMI2N

79
78

Transmit Monitor Output:
Redundant transmit driver enabled by RCSL control.

TXCKP

TXCKN

96
97

Transmit Serial Clock Output:
A 2x line rate LVPECL clock output used to clock out the transmit data

ECLP

ECLN

100

Transmit Serial LVPECL Data Output:
Transmit NRZ data

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

PIN DESCRIPTION

(continued)

RECEIVER PINS

NAME

PIN

TYPE DESCRIPTION

PO0D
PO1D
PO2D
PO3D

41
40
37
36

Receive Data Parallel Output:
The four bit CMOS parallel outputs are clocked out on the falling edge of the
receive parallel output clock. The MSB of the output is received first.

POCK

33 CO

Receive Parallel Clock Output:
A 38.88MHz CMOS clock output generated by dividing down the recovered
receive clock. The output is multiplexed in from the divided down reference
clock whenever LOS is high.

SODP
SODN

20
21

Receive Serial Data Output:
Recovered receive serial data

SOCKP
SOCKN

18
19

Receive Serial Clock Output:
Recovered receive serial clock

RXP
RXN

90
91

A/
PI

Receive Serial CMI or LVPECL Input:
The input signal is either transformer coupled for CMI data or at LVPECL
levels for NRZ data

REFERENCE AND STATUS PINS

NAME

PIN

TYPE DESCRIPTION

CKREFP
CKREFN

83
82

Reference Clock Input:
A differential 139.264MHz, 155.52MHz differential clock input at CKREFP/N
or a single-ended 17.408MHz, 19.44MHz, 77.78MHz CMOS clock input at
CKREFP (tie CKREFN to ground when unused).
All reference clocks are +/- 20ppm.

LOS

61 CO

Loss of Signal:
Standards compliant loss of signal indicator. To be used for electrical CMI
interfaces only.

LOL

60 CO

Loss of Lock:
This condition is met when the recovered clock frequency differs from the
reference clock frequency by more than +/- 1000ppm.

INTTX

67 CO

Transmitter Fault Interrupt Flag (active low):
When a transmitter error event occurs (as defined in the Interrupt Control
Register Description), the

INTTX pin will change state to indicate an

interrupt. The interrupt is cleared by a read to the STAT Register or issue of
a FRST FIFO reset pulse if the FIERR signal caused the interrupt. The
default interrupt condition is a loss of lock in the transmitter CDR.

INTRX

52 CO

Receiver Fault Interrupt Flag (active low):
When a receiver error event occurs (as defined in the Interrupt Control
Register Description), the

INTRX pin will change state to indicate an

interrupt. The interrupt is cleared by a read to the STAT Register. The
default interrupt condition is a CMI line code violation.

POR

64 A

Power-On Reset (active low):
See Power-On Reset description on use of this pin.

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

PIN DESCRIPTION

(continued)

CONTROL PINS

NAME

PIN

TYPE DESCRIPTION

FRST

59 CIT

FIFO Phase-Initialization Control:
Should normally be floating or high. When asserted, the transmit FIFO
pointers are reset to the respective "centered" states. Also resets the FIERR
interrupt bit. De-assertion edge of FRST will resume FIFO operation.

Low: FRST assertion.

Float/High: Normal

NOTE: Transmit Monitor port is also affected during a FIFO reset.

RCSL

14 CID

Redundant Channel Selection:
Enables the redundant Transmit Monitor Output at pins CMI2P/N.

Low: Normal operation (CMIP/N active only)

High: Transmit Monitor Mode (CMIP/N and CMI2P/N active)

LPBK

15 CIT

Loopback Selection:

Low: Normal operation

Float: Remote Loopback Enable: Recovered receive data and clock
are looped back to the transmitter for retransmission.

High: Local Loopback Enable: The serial transmit data is looped back
and used as the input to the receiver.

CKMODE

13 CIT

Clock Mode Selection:
In PARALLEL mode (SDI_PAR high):

Low/Float: Parallel transmit clock is input to the 78P2351

High: Parallel transmit clock is output from the 78P2351

In SERIAL mode (SDI_PAR low):

Low: Reference clock is synchronous to transmit clock and data. Data
is passed through a FIFO

Float: Reference clock is synchronous to transmit data. Clock is
recovered with a CDR and data is passed through a FIFO

High: Reference clock is plesiochronous to transmit data. Clock is
recovered with a CDR and the FIFO is bypassed

TXOUT1

1 CIT

CMI Driver Peaking Control:

Functionality TBD. Should be floating for normal operation

TXOUT0

2 CIT

CMI Driver Amplitude Control:

Functionality TBD. Should be tied low for normal operation

TXPD

12 CID

Transmitter Power Down:
When high, powers down the transmitter. The transmit monitor port, if
enabled, is also powered down when TXPD is high.

SPSL

58 CID

Serial Port Selection:
When high, chip is SW controlled through the serial port.

CKSL

62 CIT

Reference Clock Frequency Selection:
Selects the reference frequency that is supplied at the CKREFP/N pins. Its level
is read in only at power-up or on the rising edge of a reset signal at the

POR pin.

Low: 19.44MHz or 17.408MHz

Float: 77.76MHz

High: 155.52MHz or 139.264MHz

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

PIN DESCRIPTION

(continued)

SERIAL-PORT PINS

NAME

PIN

TYPE DESCRIPTION

SEN_CMI 72

[SPSL=1] Serial-Port Enable:

High during read and write operations. Low disables the serial port.
While SEN is low, SDO remains in high impedance state, and SDI and
SCK activities are ignored.

[SPSL=0] Medium Select:

Low: ECL (NRZ) mode
Float: CMI mode (input/output polarity inverted)
High: CMI mode (normal input/output)

SCK_MON 73

CIS

[SPSL=1] Serial Clock:

Controls the timing of SDI and SDO.

[SPSL=0] Receive Monitor Mode Enable:

When high, adds 20dB of flat gain to the incoming signal before
equalization. NOTE: Rx Monitor mode is only available in CMI mode.

SDI_PAR 71

[SPSL=1] Serial Data Input:

Inputs mode and address information. Also inputs register data during
a Write operation. Both address and data are input least significant bit
first.

[SPSL=0] Data Width Select:

Selects 4 bit parallel (input high) or serial mode (input low)

SDO_E4 70

COZ/

[SPSL=1] Serial Data Output:

Outputs register information during a Read operation. Data is output
least significant bit first

[SPSL=0] Rate Select:

Selects E4 operation (input high) or STM1/STS3 operation (input low)

POWER AND GROUND PINS

It is recommended that all supply pins be connected to a single power supply plane and all ground pins be
connected to a single ground plane.

NAME

PIN

TYPE DESCRIPTION

VCC

3, 10, 16, 56,

66, 69, 76, 80,

88, 92, 98

S Power

Supply

VDD

31, 35, 39, 43

CMOS Driver Supply

GND

4, 11, 17, 55,

63, 65, 68, 77,
84, 85, 86, 87,

89, 95

G Ground

VSS

30, 34, 38, 42

CMOS Driver Ground

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

Operation beyond these limits may permanently damage the device.

PARAMETER

RATING

Supply Voltage (Vdd)

-0.5 to 4.0 VDC

Storage Temperature

-65 to 150 °C

Junction Temperature

-40 to 125 °C

Theta-JA (

) Still Air

50 °C/W

Pin Voltage (CMIxP,CMIxN)

Vdd + 1.5 VDC

Pin Voltage (all other pins)

-0.3 to (Vdd+0.6) VDC

Pin Current

100 mA

RECOMMENDED OPERATING CONDITIONS

Unless otherwise noted all specifications are valid over these temperatures and supply voltage ranges.

PARAMETER

RATING

DC Voltage Supply (Vdd)

3.15 to 3.45 VDC

Ambient Operating Temperature

-40 to 85°C

DC CHARACTERISTICS:

PARAMETER

SYMBOL

CONDITIONS

MIN

NOM

MAX

UNIT

Supply Current
(including transmitter current
through transformer)

Idd

VP = 3.3V
STM-1 mode
CMI mode
Max. cable length
Tx Monitor Enabled

TBD

Supply Current per Port
(including transmitter current
through transformer)

Iddx

VP = 3.3V
STM-1 mode
CMI mode
Max. cable length
Tx Monitor Disabled

TBD

Supply Current

Idde

VP=3.3V
STM-1 mode
NRZ (optical) mode

TBD mA

Supply Current

Iddr

VP = 3.3V
Transmitter disabled
STM-1 mode
CMI mode
Max. cable length

TBD

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

ANALOG PINS CHARACTERISTICS:

The following table is provided for informative purpose only. Not tested in production.

PARAMETER

SYMBOL

CONDITIONS

MIN

NOM

MAX

UNIT

RXP and RXN
Common-Mode Bias Voltage

Vblin

Ground Reference

2.1 V

RXP and RXN Differential
Input Impedance

Rilin

10 k

Analog Input/Output
Capacitance

Cin

8 pF

DIGITAL I/O CHARACTERISTICS:

Pins of type CI, CIU, CID:

PARAMETER

SYMBOL

CONDITIONS

MIN

NOM

MAX

UNIT

Input Voltage Low

Vil

0.8

Input Voltage High

Vih

2.0

Input Current

Iil, Iih

Pull-up Resistance

Rpu

Type CIU only

Pull-down Resistance

Rpd

Type CID only

Input Capacitance

Cin

Pins of type CIS:

PARAMETER

SYMBOL

CONDITIONS

MIN

NOM

MAX

UNIT

Low-to-High

Threshold

Vt+

1.5 V

High-to-Low

Threshold

Vt-

0.9 V

Input Current

Iil, Iih

Input Capacitance

Cin

Pins of type CO and COZ:

PARAMETER

SYMBOL

CONDITIONS

MIN

NOM

MAX

UNIT

Output Voltage Low

Vol

Iol = 8mA

0.4

Output Voltage High

Voh

Ioh = -8mA

2.4

Output Transition Time

= 20pF

Tri-state Output Leakage
Current

Iz Type

COZ

only

Pins of type PO:

PARAMETER

SYMBOL

CONDITIONS

MIN

NOM

MAX

UNIT

Output Voltage Low

Vol

Vdd referenced

-1.4

Output Voltage High

Voh

Vdd referenced

-0.9

Rise Time

Fall Time

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

TRANSMITTER SPECIFICATIONS FOR CMI INTERFACE

Bit Rate: 139.264Mbit/s

15ppm or 155.52Mbits/s

20ppm

Code: coded mark inversion (CMI)
Relevant Specification: ITU-T G.703

With the coaxial output port driving a 75

load, the output pulses conform to the templates in Figures 11, 12, 13

and 14. These specifications are tested during production test.

PARAMETER

CONDITION

MIN

NOM

MAX

UNIT

Peak-to-peak Output Voltage

Template, steady state

0.9

1.1

Rise/ Fall Time

10-90%

Transition Timing Tolerance

Negative Transitions
Positive Transitions at Interval
Boundaries
Positive Transitions at mid-
interval

-0.1
-0.5

-0.35

0.1

0.5

0.35

ns
ns

The following specifications are not tested during production test. They are included for information only.
Note that the return loss depends on the board layout and the particular transformer used.

PARAMETER

CONDITION

MIN

NOM

MAX

UNIT

Return Loss

7MHz to 240MHz

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

(Note 1)

0.60

0.55

0.50

0.45

0.40

0.05

-0.05

-0.50

-0.55

-0.60

-0.45

-0.40

(Note 1)

0.35ns

Nominal

Zero Level

(Note 2)

T = 7.18ns

0.1ns

1ns

1.795 ns

1ns

0.1ns

1ns

Nominal

Pulse

0.35ns

Note 1 The maximum "steady state" amplitude should not exceed the 0.55V limit. Overshoots and other transients are permitted to fall into
the shaded area bounded by the amplitude levels 0.55V and 0.6V, provided that they do not exceed the steady state level by more than
0.05V.

Note 2 For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01

F, to the input of

the oscilloscope used for measurements. The nominal zero level for both masks should be aligned with the oscilloscope trace with no input
signal. With the signal then applied, the vertical position of the trace can be adjusted with the objective of meeting the limits of the masks. Any
such adjustment should be the same for both masks and should not exceed

0.05V. This may be checked by removing the input signal again

and verifying that the trace lies with

0.05V of the nominal zero level of the masks.

Note 3 Each pulse in a coded pulse sequence should meet the limits of the relevant mask, irrespective of the state of the preceding or
succeeding pulses, with both pulse masks fixed in the same relation to a common timing reference, i.e. with their nominal start and finish
edges coincident. The masks allow for HF jitter caused by intersymbol interference in the output stage, but not for jitter present in the timing
signal associated with the source of the interface signal. When using an oscilloscope technique to determine pulse compliance with the mask,
it is important that successive traces of the pulses overlay in order to suppress the effects of low frequency jitter. This can be accomplished by
several techniques [e.g. a) triggering the oscilloscope on the measured waveform or b) providing both the oscilloscope and the pulse output
circuits with the same clock signal].

Note 4 For the purpose of these masks, the rise time and decay time should be measured between 0.4V and 0.4V, and should not exceed
2ns.

Figure 11 Mask of a Pulse corresponding to a binary Zero in E4 mode

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

(Note 1)

0.60

0.55

0.50

0.45

0.40

0.05

-0.05

-0.50

-0.55

-0.60

-0.45

-0.40

(Note 1)

Nominal

Zero Level

(Note 2)

T = 7.18ns

0.1ns

1ns

1.795 ns

1ns

Nominal

Pulse

3.59ns

1.35ns

3.59ns

1.795 ns

1ns

0.5ns

Note 2 For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01

F, to the input of

0.05V. This may be checked by removing the input signal again

and verifying that the trace lies with

0.05V of the nominal zero level of the masks.

Note 4 For the purpose of these masks, the rise time and decay time should be measured between 0.4V and 0.4V, and should not exceed
2ns.

Note 5 The inverse pulse will have the same characteristics, noting that the timing tolerance at the level of the negative and positive
transitions are

0.1ns and

0.5ns respectively.

Figure 12 Mask of a Pulse corresponding to a binary One in E4 mode.

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

(Note 1)

0.60

0.55

0.50

0.45

0.40

0.05

-0.05

-0.50

-0.55

-0.60

-0.45

-0.40

(Note 1)

0.35ns

Nominal

Zero Level

(Note 2)

T = 6.43ns

0.1ns

1ns

1.608ns

1ns

0.1ns

1ns

Nominal

Pulse

0.35ns

Note 2 For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01

F, to the input of

0.05V. This may be checked by removing the input signal again

and verifying that the trace lies with

0.05V of the nominal zero level of the masks.

Note 4 For the purpose of these masks, the rise time and decay time should be measured between 0.4V and 0.4V, and should not exceed
2ns.

Figure 13 Mask of a Pulse corresponding to a binary Zero in STM-1/STS-3 mode.

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

(Note 1)

0.60

0.55

0.50

0.45

0.40

0.05

-0.05

-0.50

-0.55

-0.60

-0.45

-0.40

(Note 1)

Nominal

Zero Level

(Note 2)

6.43ns

0.1ns

1ns

1.608ns

1ns

Nominal

Pulse

3.215ns

1.2ns

3.215ns

1.608ns

1ns

0.5ns

Note 2 For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01

F, to the input of

0.05V. This may be checked by removing the input signal again

and verifying that the trace lies with

0.05V of the nominal zero level of the masks.

Note 4 For the purpose of these masks, the rise time and decay time should be measured between 0.4V and 0.4V, and should not exceed
2ns.

Note 5 The inverse pulse will have the same characteristics, noting that the timing tolerance at the level of the negative and positive
transitions are

0.1ns and

0.5ns respectively.

Figure 14 Mask of a Pulse corresponding to a binary One in STM-1/STS-3 mode

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

RECEIVER (Transformer-coupled)

PARAMETER

CONDITION

MIN

TYP

MAX

UNIT

Peak Differential Input
Amplitude, RXP and RXN

CMI mode; MON=0.

500 mVpk

Peak Differential Input
Amplitude, RXP and RXN

CMI mode; MON=1

mVpk

Flat-loss Tolerance

CMI mode; MON=0.
All valid cable lengths.

2 dB

Receive Clock Jitter

STM-1 mode; CMI mode
with maximum cable
a) Normal receive mode
b) Remote

loopback

mode

0.1

0.07

UIpp
UIpp

RECEIVER SPECIFICATIONS FOR CMI INTERFACE

The input signal is assumed compliant with ITU-T G.703 and can be attenuated by the dispersive loss of a
cable. The minimum cable loss is 0dB and the maximum is 12dB at 70MHz.
The "Worst Case" line corresponds to the ITU-T G.703 recommendation. The "Typical" line corresponds to a
typical installation referred to in ANSI T1.102-1993. The receiver is tested using the cable model. It is a lumped
element approximation of the "Worst Case" line.

Figure 15: Typical and worst-case Cable attenuation

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

Frequency (Hz)

tten

a
ti

)

Worst Case

Typical

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

ELECTRICAL SPECIFICATIONS

(continued)

RECEIVER JITTER TOLERANCE

The 78P2351 is compliant with all relevant jitter tolerance specifications shown in Figures 16, 17. STS-3/OC-3
jitter tolerance specifications are in ANSI T1.105.03-1994 and Telcordia GR-253-CORE. STM-1 (optical) jitter
tolerance specifications are in ITU-T G.813, G.825, and G.958. STM-1e (electrical) jitter tolerance
specifications are in ITU-T G.825. E4 specifications are found in ITU-T G.823. Receive jitter tolerance is not
tested during production test.

0.01

0.1

100

1.E+00

10Hz

100Hz

1kHz

10kHz

100kHz

1MHz

10MHz

Electrical (CMI) Interfaces

G.825 - STM-1e Tolerance
(for 2048 kbps networks)

G.825 - STM-1e Tolerance
(for 1544 kbps networks)

Jitter Frequency

Jit

t
e
r

To

ler

a
nc

e (

I
pp

)

G.823 - E4 Tolerance

Figure 16: Jitter Tolerance - electrical (CMI) interfaces

PARAMETER

CONDITION

MIN

NOM

MAX

UNIT

E4 Jitter Tolerance

200Hz to 500Hz
10kHz to 3.5MHz

1.5

0.075

STM-1e Jitter Tolerance

10Hz to 19.3Hz
68.7Hz to 6.5kHz
65kHz to 1.3MHz

38.9

1.5

0.15

UIpp

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

APPLICATION INFORMATION

EXTERNAL COMPONENTS:

COMPONENT

PIN(S)

VALUE

UNITS

TOLERANCE

Receiver Termination Resistor

RXP

RXN

Transmitter Termination Resistor

CMIP

CMIN

TRANSFORMER SPECIFICATIONS:

COMPONENT

VALUE

UNITS

TOLERANCE

Turns Ratio for the Receiver

1:1

Turns Ratio for the Transmitter (center-tapped)

1:1

Suggested Manufacturer: Pulse, MiniCircuits

RECOMMENDED LVPECL TERMINATIONS:

= 50

100

200

O/E converter

OC3 Framer

RXP/N

SIDP/N

Figure 19: Differential LVPECL Inputs

E/O Converter

= 50

100

200

ECLP/N

Figure 20: Differential LVPECL Outputs

78P2351 Single Channel OC-3/STM1-E/E4 Line Interface Unit

PACKAGE INFORMATION

(Top View)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

63
62
61
60
59
58
57
56
55
54
53
52
51

100

ECL

ECLP

VCC

TXCKN

TXCKP

CMI

VCC

RXN

RXP

VCC

CKR

VCC

CMI

2
P

CMI

2
N

VCC

CKR

PO1D

PO0D

PO2D

PO3D

TXOUT1

TXOUT0

VCC

GND

VCC

SIDN

SODN

PICK

PI0D

PI1D

SICKP

SICKN

N/C

SIDP

N/C

VCC

GND

TXPD

CKMODE

SOCKP

GND

SOCKN

SODP

LPBK

RCSL

GND

POR

CKSL
LOS

GND

SDI_PAR
SDO_E4

N/C
N/C
SCK_MON
SEN_CMI

LOL
FRST
SPSL

INTTX
VCC
GND

GND
N/C
N/C
INTRX
N/C

VCC

N/C

78P2351-IGT

Target Datasheet:

This Target Datasheet is proprietary to TDK Semiconductor Corporation (TSC) and sets forth design goals for the

described product. The data sheet is subject to change. TSC assumes no obligation regarding future manufacture, unless agreed to in
writing.

If and when manufactured and sold, this product is sold subject to the terms and conditions of sale supplied at the time of order
acknowledgment, including those pertaining to warranty, patent infringement and limitation of liability. TDK Semiconductor Corporation
(TSC) reserves the right to make changes in specifications at any time without notice. Accordingly, the reader is cautioned to verify that a
data sheet is current before placing orders. TSC assumes no liability for applications assistance.

TDK Semiconductor Corp., 2642 Michelle Dr., Tustin, CA 92780

TEL (714) 508-8800, FAX (714) 508-8877, http://www.tdksemiconductor.com

2003 TDK Semiconductor Corporation

04/03/03 rev 1.5

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: 78P2351-IGT

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: 78P2351-IGT