Trimmer Nintendo DS Lite plays up consumer appeal

Nintendo Co. Ltd is enjoying a renaissance in gaming, so it seemed like a good time to peek into its current offering in portables. While a recent Nintendo Wii teardown by Portelligent tells a fascinating story of higher-end graphics and motion-sensing controllers, the lower-profile handheld game platforms are still a big part of the company's bottom line, and they're notable for their engineering.

The Nintendo DS Lite is a second-generation offering to the original Nintendo Dual Screen (DS) launched in November 2004. The DS Lite, whose staged worldwide rollout began March 2006 in Japan, shaves 20 percent of the weight and 40 percent of the volume off its predecessor design but retains the signature two-panel display arrangement for an improved gaming experience.

Smarter game play
While the single-screen Game Boy and Game Boy Advance got the ball rolling for Nintendo, the company saw that more display area—and specifically more displays—could distinguish the design and provide for novel use modes and richer game play. Rather than just going bigger, the display double-up provides distinct interfaces that can each take on different roles. To that end, while both LCD modules use essentially the same panel from Sharp (256 x 192, 18bit color TFT), only the lower display has a touchscreen overlay.

The Nintendo DS Lite provides two stereo speakers for virtual surround sound and an embedded microphone for games that require voice recognition. The unit also provides ports for both Nintendo DS and Game Boy Advance cartridges, along with terminals for the stereo headphone and microphone.

Wireless communication is embedded within the DS Lite, based here on 802.11 with a Nintendo proprietary communications protocol. Specified range is about 9-30m. Along with allowing multiplayer games by wireless link, the modified Wi-Fi can also link up with the Nintendo Wii. Like the original Nintendo DS, the Lite allows users to select from English, Japanese, Spanish, French, German or Italian.

Battery capacity has been bumped up in the Lite revision, from the 850mA-hr Li-ion battery of the DS to a full 1,000mA-hr capacity—enough juice to fund a claimed five to 19hrs of use time on a 4hr charge.

Mystery chip
Electronics for the Nintendo DS Lite center on a custom ARM-based CPU and graphics processor (CPU NTR B) containing both ARM-9 and ARM-7 cores. The former is presumed to do the media processing, while the latter handles control functions. The NTR B is supported by what is likely 4Mbytes of NEC Electronics p-SRAM (?PD4632512F1), though NEC lists only a ?PD4632312A on its Website, so some customization and ambiguity seem to be the case there.

Analog content for both system power management and audio come in an ASIC from Mitsumi Electric (MM3205B). The only remaining analog function outside of wireless is the touchscreen controller, which is based on AKM Semiconductor's AK4181, supplanting Texas Instruments' TSC20461 used in the original DS design.

Nintendo: more display area—and more displays—could provide richer game play. (View Nintendo DS Lite's teardown diagram)

The WLAN subsystem is a plug-in daughter card module that is a more-simplified version of the first-generation DS. Mitsumi again supplies the Wi-Fi connectivity with its MM3218, substituting a single-chip device for the separate baseband and transceiver chips of the original DS connectivity solution.

While not shown here, the MM3218 appears visually at the die level to contain largely analog radio circuitry, suggesting that some of the baseband/MAC layer may be implemented back in the NTR B chip referenced earlier. Since the MM3218 is a custom part, there is no way to lean on a data sheet for guidance on this point. An oddly numbered STMicroelectronics memory chip suspected to be 256kbytes of serial flash memory handles the MM3218's local code-store needs. Using local memory suggests at least some of the Wi-Fi digital processing solution is resident on the Mitsumi chip.

A daughter card implementation for Wi-Fi—while bucking the simplicity trend—has its advantages. As with the Apple TV teardown, the separation of function allows for independent FCC certification of the wireless bits, limiting early exposure of the DS Lite design as a whole and allowing the Wi-Fi to be upgraded on a path isolated from that of the rest of the DS Lite.

The Lite update to the Nintendo DS is no surprise in view of the platform's success. With 20 million of the original sold, cost reduction represents a good investment. In addition, cosmetic enhancements join up with component count reductions in the DS Lite to improve consumer appeal and production costs.

By David Carey
President, Portelligent