DS21FT44 Datasheet, PDF (17/110 Pages) Dallas Semiconductor – 4x3 Twelve Channel E1 Framer, 4x4 Sixteen Channel E1 Framer

5. DS21Q44 DIE DESCRIPTION
DS21FT44/DS21FF44
FEATURES
· ^{Four E1 (CEPT or PCM-30) /ISDN-PRI}
framing transceivers
· ^{All four framers are fully independent;}
transmit and receive sections of each
framer are fully independent
· ^{Frames to FAS, CAS, CCS, and CRC4}
formats
· ^{Each of the four framers contain dual two–}
frame elastic store slip buffers that can
connect to asynchronous backplanes up to
8.192 MHz
· ^{8–bit parallel control port that can be used}
directly on either multiplexed or non–
multiplexed buses (Intel or Motorola)
· ^{Easy access to Si and Sa bits}
· ^{Extracts and inserts CAS signaling}
· ^{Large counters for bipolar and code}
violations, CRC4 code word errors, FAS
word errors, and E-bits
· ^{Programmable output clocks for Fractional}
E1, per channel loopback, H0 and H12
applications
· ^{Integral HDLC controller with 64-byte}
buffers. Configurable for Sa bits or DS0
operation
· ^{Detects and generates AIS, remote alarm,}
and remote multiframe alarms
· ^{Pin compatible with DS21Q42 Enhanced}
Quad T1 Framer
· ^{3.3V supply with 5V tolerant I/O; low}
power CMOS
· ^{Available in 128–pin TQFP package}
· ^{IEEE 1149.1 support}
FUNCTIONAL DIAGRAM
Receive
Framer
Elastic
Store
Transmit
Formatter
FRAMER #0
FRAMER #1
FRAMER #2
FRAMER #3
Elastic
Store
Control Port
DESCRIPTION
The DS21Q44 E1 is an enhanced version of the DS21Q43 Quad E1 Framer. The DS21Q44 contains four
framers that are configured and read through a common microprocessor compatible parallel port. Each
framer consists of a receive framer, receive elastic store, transmit formatter and transmit elastic store. All
four framers in the DS21Q44 are totally independent, they do not share a common framing synchronizer.
Also the transmit and receive sides of each framer are totally independent. The dual two-frame elastic
stores contained in each of the four framers can be independently enabled and disabled as required. The
device fully meets all of the latest E1 specifications including CCITT/ITU G.704, G.706, G.962, and
I.431 as well as ETS 300 011 and ETS 300 233.
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