DS2148 Dallas Semiconducotr, DS2148 Datasheet - Page 36

• Manufacturer Part Number: DS2148
• Description: 5V E1/T1/J1 Line Interface
• Manufacturer: Dallas Semiconducotr

RECEIVED ALARM CRITERIA Table 7-1
NOTES:
1) Receive carrier loss (RCL) is also known as loss-of-signal (LOS) or Red Alarm in T1.
2) See CCR1.5 for details.
SR (06H): STATUS REGISTER
(MSB)
LUP
ALARM
SYMBOL
(real time)
(real time)
(real time)
(real time)
RUA1
RUA1
(latched)
(latched)
(latched)
(latched)
RCL
RCL
PRBSD
TOCD
LOTC
RUA1
TCLE
LDN
RCL
LUP
1
1
LDN
E1/T1
POSITION
E1
T1
E1
T1
SR.7
SR.6
SR.5
SR.4
SR.3
SR.2
SR.1
SR.0
LOTC
Less than two zeros in two
frames (512 bits)
Over a 3ms window, five or less
zeros are received
255 (or 2048)
received
(G.775)
192 (or 1544)
are received
DESCRIPTION
Loop Up Code Detected. Set when the loop up code defined in
registers RUPCD1 and RUPCD2 is being received. See Section
6 for details.
Loop Down Code Detected. Set when the loop down code
defined in registers RDNCD1 and RDNCD2 is being received.
See Section 6 for details.
Loss of Transmit Clock. Set when the TCLK pin has not
transitioned for 5msec (±2msec). Will force the LOTC pin high.
Receive Unframed All Ones. Set when an unframed all ones
code is received at RRING and RTIP. See Table 7-1for details.
Receive Carrier Loss. Set when a receive carrier loss condition
exists at RRING and RTIP. See Table 7-1for details.
Transmit Current Limit Exceeded. Set when the 50mA (rms)
current limiter is activated whether the current limiter is enabled
or not.
Transmit Open Circuit Detect. Set when the device detects
that the TTIP and TRING outputs are open circuited.
PRBS Detect. Set when the receive-side detects a 2
a 2
RUA1
20
SET CRITERIA
-1 (T1) Pseudo Random Bit Sequence (PRBS).
2
2
consecutive zeros
consecutive zeros
36 of 75
RCL
TCLE
More than two zeros in two
frames (512 bits)
Over a 3ms window, six or more
zeros are received
In 255 bit times, at least 32 ones
are received
14 or more ones out of 112
possible bit positions are
received starting with the first
one received
CLEAR CRITERIA
TOCD
15
-1 (E1) or
PRBSD
(LSB)