Framer E1/T1 3.3V 128-Pin TQFP

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. The transmit and receive sides of each framer are also 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.

• 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 twoframe elastic-store slip buffers that can connect to asynchronous backplanes up to 8.192MHz
• 8-bit parallel control port that can be used directly on either multiplexed or nonmultiplexed 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