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