DS3171N+ Maxim Integrated Products, DS3171N+ Datasheet - Page 88

• Manufacturer Part Number: DS3171N+
• Description: TXRX SGL DS3/E3 400PBGA
• Manufacturer: Maxim Integrated Products

Specifications of DS3171N+

• Function: Single-Chip Transceiver
• Interface: DS3, E3
• Number Of Circuits: 1
• Voltage - Supply: 3.135 V ~ 3.465 V
• Current - Supply: 273mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 400-BGA
• Includes: DS3 Framers, E3 Framers, HDLC Controller, On-Chip BERTs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -
• Other names: 90-31710+N00

DS3171/DS3172/DS3173/DS3174
10.6.6.5.3 Receive DS3 Downstream AIS Generation
Downstream DS3 AIS (all ‘1’s) can be automatically generated on an OOF, LOS, or AIS condition or manually
inserted. If automatic downstream AIS is enabled, downstream AIS is inserted when an LOS or AIS condition is
declared, or no earlier than 2.25 ms and no later than 2.75 ms after an OOF condition is declared. Automatic
downstream AIS is programmable (on or off). If manual downstream AIS insertion is enabled, downstream AIS is
inserted. Manual downstream AIS insertion is programmable (on or off). Downstream AIS is removed when all
OOF, LOS, and AIS conditions are terminated and manual downstream AIS insertion is disabled.
10.6.7 G.751 E3 Framer/Formatter
10.6.7.1 Transmit G.751 E3 Frame Processor
The G.751 E3 frame format is shown in
Figure
10-17. FAS is the Frame Alignment Signal. A is the Alarm indication
bit used to indicate the presence of an alarm to the remote terminal equipment. N is the National use bit reserved
for national use.
Figure 10-17. G.751 E3 Frame Format
FAS
A N
4 Rows
1524 Bit Payload
384 bits
10.6.7.2 Transmit G.751 E3 Frame Generation
G.751 E3 frame generation receives the incoming payload data stream, and overwrites all of the E3 overhead bit
locations.
The first ten bits of the frame are overwritten with the frame alignment signal (FAS), which has a value of
1111010000b.
The eleventh bit of the frame is overwritten with the alarm indication (A) bit. The A bit can be generated
automatically, sourced from the transmit FEAC controller, set to one, or set to zero. The A bit source is
programmable (automatic, FEAC, 1, or 0). If the A bit is generated automatically, it is set to one when one or more
of the indicated alarm conditions is present, and set to zero when all of the indicated alarm conditions are absent.
Automatically setting RDI on LOS, LOF, or AIS is individually programmable (on or off).
The twelfth bit of the frame is overwritten with the national use (N) bit. The N bit can be sourced from the transmit
FEAC controller, sourced from the transmit HDLC overhead controller, set to one, or set to zero. The N bit source
is programmable (FEAC, HDLC, 1, or 0). Note: The FEAC controller will source one bit per frame regardless of
whether the A bit only, the N bit only, or both are programmed to be sourced from the FEAC controller.
Once all of the E3 overhead bits have been overwritten, the data stream is passed on to error insertion. If frame
generation is disabled, the incoming E3 signal is passed on directly to error insertion. Frame generation is
programmable (on or off).
10.6.7.3 Transmit G.751 E3 Error Insertion
Error insertion inserts framing errors into the frame alignment signal (FAS). The type of error(s) inserted into the
FAS is programmable (errored FAS bit or errored FAS). An errored FAS bit is a single bit error in the FAS. An
errored FAS is an error in all ten bits of the FAS (a value of 0000101111b is inserted in the FAS). Framing error(s)
can be inserted one error at a time, or in four consecutive frames. The framing error insertion number (single or
four) is programmable.
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