DS21Q44 Datasheet, PDF (1/105 Pages) Dallas Semiconductor – Enhanced QUAD E1 FRAMER

DS21Q44
Enhanced QUAD E1 FRAMER
www.dalsemi.com
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
Elastic
Store
FRAMER #0
FRAMER #1
FRAMER #2
FRAMER #3
Control Port
ACTUAL SIZE
QUAD
E1
FRAMER
ORDERING INFORMATION
DS21Q44T (0⁰ C to 70⁰ C)
DS21Q44TN (-40⁰ C to +85⁰ C)
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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