One-Chip Solution Brings TCP/IP To 2.5G, 3G Cell Phones

Newer 2.5G and 3G cell phones are packet-based, so they can readily access the Internet if they're given TCP/IP capability. To develop such a cell phone, you can buy or download a TCP/IP stack to use on your selected internal processor. Also, you could use a processor with a built-in TCP/IP stack or an available wireless modem or Internet controller chip. Then there is the Connect One iChip CO110PC, which does the entire job while saving time and money.

This chip comes in handy when adding Internet access to GSM/GPRS, cdma2000, or WCDMA 3G cell phones. It also offers an easy route for implementing machine-to-machine (M2M) applications. M2M uses the Internet to monitor or control remote devices from a cell phone.

The CO110PC is an updatable communications peripheral chip that mediates the connection between a host device, like a cell phone, and the Internet. It works with any host processor, operating system, and cellular modem that supports the AT command set. Included are 128k of flash memory and 64 kbytes of SRAM to prevent packet loss (see the figure).

The chip handles IP, TCP, UDP, DNS, HTTP client, and PING. Optional firmware supports SMTP and FTP clients and SerialNET mode. Also incorporated are 10 simultaneous TCP and UDP sockets for multitasking during an Internet session, as well as two TCP listening sockets for acting as a server. Its internal 1.8-V ARM7-TDMI processor, which runs at up to 60 MHz, has a sleep mode for low power consumption. Packaging is a 7- by 7-mm, 48-pin LQFP.

The CO110PC links to the host processor via a standard serial host interface and serial modem interface. Speeds up to 230.4 kbits/s are supported. Future support is forthcoming for I²C, SPI, and GPIO interfaces. It also uses Connect One's AT+iT Application Programming Interface, which provides a constant and portable implementation of the TCP/IP stack for any cellular modem.

The AT+i is an extension to the industry-standard Hayes AT command set. Available now, the iChip costs $9.75 in 50,000-unit lots. A II-EVB-400 evaluation board is available for $175. See the company's Web site, which features a white paper on M2M applications in 2.5G and 3G cell phones, for details.