TFRA84J13DS0 AGERE [Agere Systems], TFRA84J13DS0 Datasheet - Page 10

• Manufacturer Part Number: TFRA84J13DS0
• Description: Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0
• Manufacturer: AGERE [Agere Systems]

TFRA84J13 Ultraframer
DS3/E3/DS2/E2/DS1/E1/DS0
5 Block Description
5.1 M13/E13 Multiplexer (M13/E13 MUX)
The M13/E13 block (three blocks per device) is a highly
configurable multiplexer/demultiplexer for which each block
can be configured for M13 or E13 operation. The features
are as described below.
5.1.1 M13 MUX
The M13 may operate in the C-bit parity or M23 mode, or a
mixed M13/M23 mode. In the C-bit parity mode, the M13
provides a far-end alarm and control (FEAC) code genera-
tor and receiver, an HDLC transmitter and receiver, and an
automatic far-end block error (FEBE) generator.
Each internal M12 MUX/deMUX and the M23 MUX/deMUX
can be configured to operate as independent MUXes/
deMUXes. 28 DS1 inputs (in groups of four) or 21 E1 input
signals (in groups of three) can feed into individual M12
MUXes, while the M23 MUX can take DS2 signals from
outputs of M12 MUXes, or direct DS2 inputs, or loopback
deMUXed DS2s.
The M13 supports numerous automatic monitoring func-
tions. It can provide an interrupt to the control system, or it
can operate in a polled mode.
The M13 complies with T1.102, T1.107, T1.231, T1.403,
T1.404, GR-499, G.747, and G.775.
5.1.1.1 Receive Direction
The receive DS3 is monitored for loss of clock and loss-of-
signal (LOS) according to T1.231. The B3ZS decoder
accepts either the unipolar clock and data, or unipolar clock
and positive and negative data. It also checks for bipolar
coding violations. The transmit DS3 can be looped back
into the receive side after B3ZS decoding. The M23 demul-
tiplexer checks for valid DS3 framing by finding the frame
alignment pattern (F-bits) and then locating the multiframe
alignment signal (M-bits). During each M frame, the data
stream is checked for the presence of the AIS (1010) or idle
(1100) pattern.
Within the M23 demultiplexer, there are four performance
monitoring counters for F-bit M-bit, P-bit, or E-bit parity, and
FEBE errors. Each M12 demultiplexer contains two perfor-
mance monitoring counters.
5.1.1.2 Transmit Direction
The incoming DS1/E1 clocks are first checked for activity or
loss-of-clock (LOC). The data signals are retimed and
checked for AIS and activity. DS1/E1 loopback selectors
allow the individual DS1/E1 signals within the received DS2
or DS3 to be looped back toward the DS2/DS3 input.
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This loopback can be performed automatically, or the user
can force a DS1 or E1 loopback.
The four DS1 or three E1 signals for each M12 MUX are
fed into single-bit, 16-word-deep FIFOs to synchronize the
signals to the DS2 frame generation clock. The fill level of
each FIFO determines the need for bit stuffing its DS1/E1
input. The M13 can handle DS1/E1 signals with nominal
frequency offsets of ±130 ppm and up to five unit intervals
peak jitter. The DS2/DS3 transmit clock is used to derive
the clock source for DS2 frame generation.
The M23 multiplexer generates a transmit DS3 frame, and
fills the information bits in the frame with data from the
seven DS2 select blocks.
The transmit DS3 output can either be in the form of unipo-
lar clock and data, or unipolar clock and positive and nega-
tive data. The DS3 data is B3ZS-encoded and can be
looped back from the receive DS3 input.
5.1.2 E13 MUX
The E13 is a functional block that performs MUX/deMUX
from/to 16 E1s, four E2s, and one E3 signal compliant with
ITU G.742 and ITU G.751. The E13 functional block is a
highly configurable multiplexer/demultiplexer. It can oper-
ate in E12, E13, or E23 modes. Each internal E12 MUX/
deMUX and E23 MUX/deMUX is independently config-
urable. The E3 inputs to the receive path can be HDB3-
encoded dual-rail (bipolar) signals or already decoded sin-
gle-rail signals with or without a BPV indication input. The
E1 and E2 inputs are expected to be decoded prior to the
E13 functional block. E3 transmit direction output can be
configured as HDB3-encoded dual rail (bipolar) or as single
rail.
The E13 provides status and two-level priority maskable
interrupt outputs to the microprocessor.
This block is also an independently configurable x4 E12
multiplexer/demultiplexer for up to 16 E1 signals to/from
four E2 signals, and has provisionable time-slot selection
for E1 and E2 insertion or drop via the multirate cross con-
nect functional block. E12/E23 multiplexers are capable of
generating alarm indicator signal (AIS) and remote alarm
indicator (RAI) signals.
E1 and E2 transmit path monitors detect loss-of-clock
(LOC) and AIS. The E2 receive path monitor detects LOC,
AIS, and RAI. The E3 receive monitor detects loss-of-signal
(LOS), LOC, bipolar violations (BPV), AIS, and RAI. E3 and
E2 loopback modes are also available.
Product Description, Revision 4
Agere Systems Inc..
April 29, 2005