DS21Q42

DS21Q42 Enhanced QUAD T1 FRAMER www.dalsemi.com FEATURES Four T1 DS1/ISDN–PRI/J1 framing transceivers All four framers are fully independent 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) Programmable output clocks for Fractional T1 Fully independent transmit and receive functionality Integral HDLC controller with 64-byte buffers configurable for FDL or DS0 operation Generates and detects in–band loop codes from 1 to 8 bits in length including CSU loop codes Pin compatible with DS21Q44 E1 Enhanced Quad E1 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 Fram er Transm it Form atter FRAMER #0 FRAMER #1 FRAMER #2 FRAMER #3 Control Port Elastic Store Elastic Store ACTUAL SIZE QUAD T1 FRAMER ORDERING INFORMATION DS21Q42T (00 C to 700 C) DS21Q42TN (-400 C to +850 C) DESCRIPTION The DS21Q42 is an enhanced version of the DS21Q41B Quad T1 Framer. The DS21Q42 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 DS21Q42 are totally independent, they do not share a common framing synchronizer. Also t...