ds21ft40 Maxim Integrated Products, Inc., ds21ft40 Datasheet - Page 30

• Manufacturer Part Number: ds21ft40
• Description: Ds21ft40 Four X Three 12 Channel E1 Framer
• Manufacturer: Maxim Integrated Products, Inc.

AUTOMATIC ALARM GENERATION
The DS21FT40 can be programmed to automatically transmit AIS or Remote Alarm. When automatic
AIS generation is enabled (CCR2.5 = 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 one’s) reception,
or loss of receive carrier (or signal). If any one (or more) of the above conditions is present, then the
framer will transmit an AIS alarm.
When automatic RAI generation is enabled (CCR2.4 = 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 one’s) reception, loss of receive carrier or if CRC4 multiframe synchronization (if enabled) cannot be
found within 128 ms of FAS synchronization. If any one (or more) of the above conditions is present,
then the framer will transmit a RAI alarm. RAI generation conforms to ETS 300 011 specifications and a
constant Remote Alarm will be transmitted if the framer cannot find CRC4 multiframe synchronization
within 400 ms as per G.706.
It is an illegal state to have both CCR2.4 and CCR2.5 set to one at the same time.
CCR3: COMMON CONTROL REGISTER 3 (Address=1B Hex)
(MSB)
TESE
SYMBOLS
SYMBOLS
TCBFS
TIRFS
TESE
RFE
–
TCBFS
POSITION
POSITION
CCR2.0
CCR3.7
CCR3.6
CCR3.5
CCR3.4
TIRFS
NAME AND DESCRIPTION
Receive Freeze Enable. See Section 9 for details.
NAME AND DESCRIPTION
Not Assigned. Should be set to zero when written.
0=no freezing of receive signaling data will occur
1=allow freezing of receive signaling data at RSER (if
CCR3.3=1).
Transmit Side Elastic Store Enable.
0=elastic store is bypassed
1=elastic store is enabled
Transmit Channel Blocking Registers (TCBR) Function Select.
0=TCBRs define the operation of the TCHBLK output pin (not
applicable for DS21FT40)
1=TCBRs define which signaling bits are to be inserted
Transmit Idle Registers (TIR) Function Select. See Section 10
for details.
0=TIRs define in which channels to insert idle code
1=TIRs define in which channels to insert data from RSER
(i.e., Per Channel Loopback function)
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RSRE
THSE
TBCS
RCLA
(LSB)
DS21FT40