DS33R41 Maxim Integrated Products, DS33R41 Datasheet - Page 73

• Manufacturer Part Number: DS33R41
• Description: Network Controller & Processor ICs Inverse-Multiplexing Ethernet Mapper wit
• Manufacturer: Maxim Integrated Products

10.5.1 Automatic Alarm Generation
The device can be programmed to automatically transmit AIS or remote alarm. When automatic AIS generation is
enabled (TR.E1TCR2.1 = 1), the device monitors the receive-side framer to determine if any of the following
conditions are present: loss-of-receive frame synchronization, AIS alarm (all ones) reception, or loss-of-receive
carrier (or signal). The framer forces either an AIS or remote alarm if any one or more of these conditions is
present.
When automatic RAI generation is enabled (TR.E1TCR2.0 = 1), the framer monitors the receive side to determine
if any of the following conditions are present: loss-of-receive-frame synchronization, AIS alarm (all ones) reception,
loss-of-receive carrier (or signal), or if CRC4 multiframe synchronization cannot be found within 128ms of FAS
synchronization (if CRC4 is enabled). If any one or more of these conditions is present, then the framer transmits
an RAI alarm. RAI generation conforms to ETS 300 011 specifications and a constant remote alarm is transmitted
if the device cannot find CRC4 multiframe synchronization within 400ms as per G.706.
Note: It is an invalid state to have both automatic AIS generation and automatic remote alarm generation enabled
at the same time.
Table 10-4. E1 Alarm Criteria
V52LNK
ALARM
RDMA
RLOS
RUA1
RRA
RCL
An RLOS condition exists on power-up
prior to initial synchronization, when a
resync criteria has been met, or when a
manual resync has been initiated by
TR.E1RCR1.0
255 or 2048 consecutive 0s received as
determined by TR.E1RCR2.0
Bit 3 of nonalign frame set to 1 for three
consecutive occasions
Fewer than three 0s in two frames (512
bits)
Bit 6 of time slot 16 in frame 0 has been set
for two consecutive multiframes
Two out of three Sa7 bits are 0
SET CRITERIA
73 of 335
At least 32 1s in 255-bit times
are received
Bit 3 of nonalign frame set to
0 for three consecutive
occasions
More than two 0s in two
frames (512 bits)
CLEAR CRITERIA
SPECIFICATION
G.775/G.962
1.6.1.2
O.162
O.162
G.965
2.1.4
ITU