IDT82V2082 Integrated Device Technology, Inc., IDT82V2082 Datasheet - Page 28

• Manufacturer Part Number: IDT82V2082
• Description: 2Ch T1/J1/E1 Short Haul/long Haul Liu
• Manufacturer: Integrated Device Technology, Inc.

DUAL CHANNEL T1/E1/J1 LONG HAUL/SHORT HAUL LINE INTERFACE UNIT
3.6
3.6.1
nal level and pulse density of the received signal on RTIPn and RRINGn.
when the signal level is less than Q dB below nominal for N consecutive
pulse intervals. Here N is defined by LAC bit (MAINT0, 0CH...). LOS will be
declared by pulling LOSn pin to high (LOS=1) and LOS interrupt will be gen-
erated if it is not masked.
when the signal level is greater than P dB below nominal and has an aver-
age pulse density of at least 12.5% for M consecutive pulse intervals, start-
ing with the receipt of a pulse. Here M is defined by LAC bit (MAINT0,
0CH...). LOS status is cleared by pulling LOSn pin to low.
Table-17 LOS Declare and Clear Criteria for Short Haul Mode
(observing windows= M)
The Loss of Signal Detector monitors the amplitude of the incoming sig-
• LOS declare (LOS=1)
A LOS is detected when the incoming signal has “no transitions”, i.e.,
• LOS clear (LOS=0)
The LOS is cleared when the incoming signal has “transitions”, i.e.,
1=T1/J1
T1E1
0=E1
density=OK
signal level>P
LOS AND AIS DETECTION
LOS DETECTION
Control bit
Figure-13 LOS Declare and Clear
0=T1.231
1=I.431
0=G.775
1=I.431/ETSI
LAC
LOS=0
Level < 800 mVpp
N=175 bits
Level < 800 mVpp
N=1544 bits
Level < 800 mVpp
N=32 bits
Level < 800 mVpp
N=2048 bits
LOS=1
(observing windows= N)
signal level<Q
LOS declare threshold
28
while P=Q+200 mVpp (200 mVpp is the LOS level detect hysteresis).
0AH...), while P=Q+4 dB (4 dB is the LOS level detect hysteresis). The
LOS[4:0] default value is 10101 (-46 dB).
if the IDT82V2082 operates in long haul mode. It is -46dB (E1) and -38dB
(T1
G.775 and ETSI 300233/I.431 for E1 mode. The criteria can be selected
by LAC bit (MAINT0, 0CH...) and T1E1 bit (GCF, 20H).
both short haul and long haul application.
tion” at the RTIPn/RRINGn side and output recovered clock (but the quality
of the output clock can not be guaranteed when the input level is lower than
the maximum receive sensitivity) when AISE bit (MAINT0, 0CH...) is 0; or
output All Ones as AIS when AISE bit (MAINT0, 0CH...) is 1. In this case
RCLKn output is replaced by MCLK.
ATAO bit (MAINT0, 0CH...) is 1. The All Ones pattern uses MCLK as the
reference clock.
• LOS detect level threshold
In short haul mode, the amplitude threshold Q is fixed on 800 mVpp,
In long haul mode, the value of Q can be selected by LOS[4:0] bit (RCF1,
When the chip is configured by hardware, the LOS detect level is fixed
• Criteria for declare and clear of a LOS detect
The detection supports the ANSI T1.231 and I.431 for T1
Table-17
• All Ones output during LOS
On the system side, the RDPn/RDNn will reflect the input pulse “transi-
On the line side, the TTIPn/TRINGn will output All Ones as AIS when
LOS indicator is always active for all kinds of loopback modes.
/J1
).
Level > 1 Vpp
M=128 bits
12.5% mark density
<100 consecutive zeroes
Level > 1 Vpp
M=128 bits
12.5% mark density
<100 consecutive zeroes
Level > 1 Vpp
M=32 bits
12.5% mark density
<16 consecutive zeroes
Level > 1 Vpp
M=32 bits
12.5% mark density
<16 consecutive zeroes
and
Table-18
summarize LOS declare and clear criteria for
LOS clear threshold
TEMPERATURE RANGES
INDUSTRIAL
/J1
mode and