The high-speed data transfer enabled by an SD interface can simplify software updates for other components in the car as well, like a head unit or other components.
These in-box use cases require true automotive-grade reliability. The new combination hub and card reader devices enable car makers to design highly reliable data access devices for their information and entertainment systems, whether those devices connect to internal peripherals or provide external consumer access.
USB HUB AND CARD READER COMBINATIONS
A USB hub expands the number of available USB ports while the card reader provides memory card interfaces, such as SD/MultimediaCard (MMC) or Sony MemoryStick. The SD interface is standardized for memory applications. It also provides a generic input/output interface known as SDIO.
The SDIO interface uses the same electrical signals as the SD memory interface but can be used to attach modules that provide additional features such as Wi-Fi, Bluetooth, and GPS connections. It is even possible to build custom firmware to control new applications attached through SDIO.
It is important for the card reader supplier to have significant experience with memory cards manufactured by many different suppliers because the specifications for the SD interface allow some room for interpretation and optional features that can result in incompatibilities with different products. SMSC has performed extensive testing to support a large number of cards currently in the market.
The current devices also support using an external ROM to create secure memory formats or add customized applications based on system requirements. Incompatibilities with cards from different manufacturers could result in warranty claims against a car maker. Service calls are very expensive, so it is important to avoid them if consumers bring in a device that they got for free somewhere.
The combination hub/card reader function allows the placement of this device away from the main host controller to provide connectivity where it is needed. For example, the glove compartment or center console in a car could allow consumers to easily connect their devices without requiring long cables to the main head unit.
CONCLUSION
USB interfaces and storage memory provide useful enhancements to automotive systems. Automotive requirements result in stringent qualification processes that only a limited number of worldwide semiconductor suppliers can implement. They also result in special features being needed to simplify system design.
Flexibility in creating multiple platforms with a single platform is a plus. Car makers also require a very high level of compatibility when dealing with memory cards from multiple suppliers. And, the devices must be able to operate in a rugged environment with high temperatures and widely varying environmental conditions.