RLOOP1, RLOOP2 : Remote Loopback (Pins 63, 27)

A remote loopback is selected when RLOOP is high. The data received from the line interface

at RTIP and RRING is looped back through the jitter attenuator and retransmitted on TTIP and

TRING. Data recovered from RTIP and RRING continues to be transmitted on RPOS and

RNEG. Data input on TPOS and TNEG is ignored. A TAOS request overrides the data

transmitted at TTIP and TRING.

TAOS1, TAOS2 : Transmit All Ones Select (Pins 60, 59)

Setting TAOS high causes continuous ones to be transmitted at the line interface on TTIP and

TRING at the frequency determined by REFCLK.

Status

DPM1, DPM2 : Driver Performance Monitor Alarm (Pins 64, 49)

The DPM alarm indication goes high when differential inputs MTIP and MRING are inactive

for 512

± 2 REFCLK periods. The DPM alarm indication returns low when MTIP and MRING

detect a minimum 12.5% ones density signal over 175

± 75 bit periods with no more than 100

consecutive zeros.

MTIP1, MTIP2 : Monitor Tip (Pins 16, 33)

MRING1, MRING2 : Monitor Ring (Pins 15, 34)

The MTIP and MRING inputs may be connected to TTIP and TRING, to detect an inactive

transmit driver. The MTIP and MRING inputs are differential and may be connected to either

transmitter output. To increase the reliability of the performance monitor, it is suggested that the

monitor inputs of one channel be connected the transmitter output pins of another channel or

device.

LOS1, LOS2 : Loss of Signal (Pins 7, 42)

The LOS indication goes high when 175

± 15 consecutive zeros are received on the line

interface. The LOS indication returns low when a minimum 12.5% ones density signal over

175

± 75 bit periods with no more than 100 consecutive zeros is received.

Test

J-TCK : JTAG Test Clock (Pin 40)

Data on pins J-TDI and J-TDO is valid on the rising edge of J-TCK. When J-TCK is stopped

low, all JTAG registers remain unchanged.

J-TMS : JTAG Test Mode Select (Pin 39)

An active high signal on J-TMS enables the JTAG serial port. This pin has an internal pull-up

resistor.

J-TDI : JTAG Test Data In (Pin 10)

JTAG data is shifted into the device on this pin. This pin has an internal pull-up resistor. Data

must be stable on the rising edge of J-TCK.

J-TDO : JTAG Test Data Out (Pin 8)

JTAG data is shifted out of the device on this pin. This pin is active only when JTAG testing is

in progress. J-TDO will be updated on the falling edge of J-TCK.

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DS224PP1