Internet Telephony Chipset Presages Single-Chip Solution

With an eye toward eventually integrating 13 functions critical to Internet telephony onto a single chip, Lucent has introduced a pair of chips that provide complete silicon for an IP telephone set residing on a local-area network. The T8301 DSP and T8302 MCU chips are said to integrate all the requisite functionality to interface directly to an Ethernet network, telephone handset, speakerphone, PDAs, and other user interfaces. The chips are a harbinger of things to come: the firm indicates that it has available all of the building blocks needed to enable users to design a customizable single-chip product. Meanwhile, the initial two-chip set will ship in the fourth quarter for less than $30 each in quantities of 100,000.The T8301 houses the set’s DSP (DSP1627), which performs speakerphone echo cancellation and voice compression. The DSP also integrates a telephone handset A/D converter (codec), a speakerphone codec, a speaker amplifier, and a microphone amplifier. The second chip, designated T8302, carries an ARM 940T microprocessor for voice-over-Internet Protocol signaling and network management. The CPU integrates: an Ethernet Media Access Controller; two Ethernet 10/100-Mbps transceiver interface drivers (PHYs) and a repeater for use of a single Ethernet wall jack for both the Internet telephone and PC; a Universal Serial Bus interface, which enables a single connection between PCs and peripheral devices such as modems; an Infrared Data Communications interface, which transfers data over an infrared channel between PCs and peripherals; a telephone keypad controller; and LCD drivers.Internet telephone systems converge voice and data on a single Ethernet wall jack, which reduces cabling costs. Such systems are initially expected to be used by medium- and small-sized businesses.