A new mixed-signal, digital signal processor (DSP)-based chipset from Texas Instruments can lower the cost of a system using a digital telephone answering device (DTAD) to the range of magnetic tape answering machines.
The chipset can incorporate advanced voice mail features such as selectively saving or deleting messages, skipping through messages quickly, speeding up playback or creating mailboxes. These features can be applied in cellular telephones and fax machines. Reliability and durability attract consumers to all-digital telephone answering systems. TI estimates that by 1997 more than 50% of the telephone answering service market will consist of DTAD (Digital Telephone Answering Device) systems. TI's DTAD chipset will allow customers to incorporate features that can make a product more competitive in the marketplace by differentiating digital answering systems from traditional magnetic tape devices.
The chipset includes the MSP58C80 mixed-signal processor, the MSP58C20 audio-band converter device and memory. TI lowered the chipset's cost by segregating analog functions onto the audio-band converter device. This allowed parts of the system to be manufactured without using more expensive analog fabrication processes. In addition, by using the core capabilities of a TMS320C25 DSP, the need for a discrete microcontroller device was eliminated, reducing system costs even further.
The core of a DTAD system can be implemented in just three devices that take up less than two square inches. Designers will be able to easily incorporate DTAD capabilities into cellular telephones, personal digital assistants, cordless phones, fax machines and pagers.
Chipset applications are supported by a full set of development and design tools. Hardware tools include full-speed in-circuit emulation. Software tools include TI's assembler/linker and C compiler which are compatible with TI's 'C25 core DSP. All tools are now available.
Fabricated as 0.8-micron devices, the MSP58C80 is available in a 100-pin quad flatpack package, and the MSP58C20 comes in a 20-pin wide-body SOIC package.