Trendy phones incorporate sophisticated engineering

With their ultraslim form factors and cool looks, Motorola's Razr and Rokr mobile phones have helped transform Motorola's image from an engineering-focused company to a hip, trend-setting, marketing company. But few know about the company's connection with India. Both phones incorporate Freescale Semiconductor's dual-core DSP56631 baseband processor and the quad-band MC13777 GPRS (general-packet-radio-service) front-end ICs-chips that Motorola designed at its Noida center.

The Indian designers were involved in the development, verification, and validation of the phones' baseband chip-a dual-core IC comprising multiple IP (intellectual-property) blocks. According to Freescale, This SOC (system-on-chip) design was the first to integrate the analog part of the RF into the baseband to reduce the overall cost of the chip set. The baseband processor integrates a Freescale DSP56600 DSP with an ARM7TDMI-S microcontroller. Functions include on-chip memory, receiver ADCs, a receive-and-transmit synthesizer, transmit power-amplifier control, and a voice codec. The front end works in GSM/DCS (Global System for Mobile communications/Digital Communications Services) and GSM850/PCS (personal-communications-services) quad-band GPRS Class 10 cellular radios. It has a receiver portion that works in VLIF (very-low-intermediate-frequency) receivers and DCRs (direct-conversion receivers).

To meet Motorola's performance and cost constraints, Freescale engineers integrated analog-baseband capability with the digital baseband in a high-speed SiGe (silicon-germanium) process. They also built low-noise amplifiers into the RF transceiver to support all four GSM bands-making the chip set smaller without sacrificing performance. One of the more difficult problems confronting the designers was deciding where to put the analog functions for both the RF chain and the audio portion. Freescale designers integrated power-management and audio features into a single chip, thereby eliminating noise-related issues and conserving space.

On the software front, Motorola's Indian development center worked on the phone's multimedia features, such as image and video capture, multimedia messaging, the user interface, the phone browser, and the GSM-signaling stacks.

Motorola, www.motorola.com.

Freescale, www.freescale.com.