CDMA handsets to shrink with
baseband system on a chip

ASIC vendor LSI Logic (Milpitas, CA) plans to extend its reach into
digital telephony with a system-on-a-chip baseband processor for code-division
multiple-access (CDMA) digital handsets. By collapsing the baseband functions
into a single chip, the company expects to shrink the baseband circuitboard
by as much as 75% and to reduce power by as much as 38%, compared with
current multichip solutions. The company expects that its lower-cost solution
will greatly expand the IS-95 CDMA market over that currently served by
Qualcomm (San Diego, CA) chipsets.

The capacity of CDMA systems is said to be better than three times that
of the TDMA systems now widespread in the US. Another vendor, ST Microelectronics
(Lincoln, MA), which has extensive experience producing system-on-chip
devices for GSM cellular service, considers CDMA to be the key technology
for the future and will be active in this market as well.

The LSI Logic chip will include two Oak DSP cores from DSP Group (Santa
Clara, CA) and an ARM7TDMI core, as well as proprietary cells carrying
all the specialized logic and analog sections for baseband processing (see
diagram ). The Oak DSP cores will handle voice and modem functions,
using on-chip code and data memory. The company expects to produce about
1,000 chips with SRAM for the DSP memory. These will serve for prototyping
only, and the settled DSP code will be in masked ROM on production units.

LSI Logic's CDMA chip packs all of a baseband processor, including
the mixed-signal parts, into a 17 x 17-mm package.

The ARM control processor will use external memory in production. It
will have sufficient processing capacity for each customer to add proprietary
features to the resulting handset.

The chip will be produced in the company's G11 ASIC process. Its digital
parts will operate at 1.8 V, and its mixed-signal sections at 3.3 V.

Customers will be provided with a complete prototype phone and RF design,
including IS-95-compliant circuitry, working protocol-stack and driver
software, keypad, display, and PCS radio.

Packaging will be in a 208-pin miniBGA with a 1-mm ball pitch, occupying
a 17 x 17-mm footprint. Also planned is a 280-pin chip-scale package with
a 0.8-mm pitch, which will cut the footprint to 16 mm on a side.

RAM-based samples of the CDMA processor will appear in the fourth quarter,
with production starting in the first quarter of 1999. For more information
from LSI Logic , call Dept. CPNR14 at 800-574-4286, fax 800-457-4286, or
visit http://www.lsilogic.com.