cx28394 Conexant Systems, Inc., cx28394 Datasheet - Page 168

• Manufacturer Part Number: cx28394
• Description: Quad/x16/octal-t1/e1/j1 Framers
• Manufacturer: Conexant Systems, Inc.

3.0 Registers
3.9 Receiver Registers
RAIS
RALOS
RLOS
3-46
Receive Alarm Indication Signal—Criteria for detection and clearance of RAIS per ITU G.775
and ANSI T1.231.
Receive Loss of Signal or Receive Clock—Reports loss of receive clock (RCKI) or loss of
receive signal [RLOS; addr 047] for 1 msec depending on the RALOS configuration bit
[RAL_CON; addr 020].
is not present, and inactive (0) if the clock is present.
msec (RLOS is active for 1 msec). This status is provided for compatibility with ITU-I.431
loss of signal detection requirements; and works in conjunction with LIUs which detect loss of
signal if the received signal level falls below a certain threshold and which have a signal
‘squelch’ feature. Operation is as follows:
Receive Loss of Signal—Criteria for detection and clearance of RLOS per ITU G.775 and
ANSI T1.231.
When set for loss of clock, RALOS becomes active (1) if the receive clock on the RCKI pin
When set for loss of signal, RALOS indicates that all zeros have been received for at least 1
• The LIU detects receive loss of signal if the receive level falls below:
• The LIU squelches (turns off) the signal to the framer so all zeros are received.
• RLOS is reported after 100 continuous zeros are detected.
• RALOS is reported after RLOS is active for 1 msec.
Mode
Mode
– 30 dB below nominal for T1.
– 20 dB below nominal for E1
E1
E1
T1
T1
T1
T1
E1
E1
RLOS
RAIS
0
1
0
1
0
1
0
1
Conexant
Cleared if 2 consecutive double frames (500 s) each
contain 3 or more zeros out of 512 bits or FAS
alignment is recovered [FRED = 0; addr 049].
Set if 2 consecutive double frames each contain 2 or
fewer zeros out of 512 bits and FAS alignment is lost
[FRED = 1; addr 049].
Cleared if data received for a period of 3 ms contains
5 or more zeros out of 4632 bits or frame alignment is
recovered [FRED = 0; addr 049].
Set if data received for a period of 3 ms contains 4 or
fewer zeros out of 4632 bits and frame alignment is
lost [FRED = 1; addr 049].
Cleared if received data sustains an average pulse
density of 12.5% over a period of 114 bits starting
with the receipt of a pulse, and no occurrence of 100
consecutive zeros.
Set if 100 consecutive zeros received.
Cleared upon reception of 193 bits in which no
interval of 32 consecutive zeros appear, where the
193-bit window begins with receipt of a pulse.
Set upon reception of 32 consecutive zeros.
Set/Clear Criteria
Set/Clear Criteria
Quad/x16/Octal—T1/E1/J1 Framers
CX28394/28395/28398
100054E