Product How-To: Use the STM65xx family to avoid false resets

by Vishal Goyal, STMicroelectronics , TechOnline India - February 12, 2010

STMicroelectronics has developed a new IC which supports safe manual restart using regular function buttons

Electronic gadgets are an integral part of life. We are dependent on devices of artificial intelligence to ease our lives. The advent of smart phones, media players, game consoles, and e-books have revolutionized the way we communicate and entertain. Mobile phones are credited with revolutionizing not only the field of telecommunication but almost each and every other aspect of the modern world.

It is frightening to imagine these gadgets getting frozen or valuable data getting lost. Without mobile phones, life would even seem to come to a halt. After traveling such a long path on the way of progress, we cannot allow ourselves to come to a standstill.

Companies today put a lot of effort into developing a product's features such as adding widgets for social networking, Windows-based interfaces, and Java applications. But adding these software-based applications also makes devices prone to getting frozen, or locking up. The more advanced the gadget the more it is prone to malfunctioning.

Most manual reset keys, where provided, are hidden to prevent resetting the devices accidentally. This is done by adding a RESET Hole in the system. This work around is not only the compromise on the aesthetics of the gadget, it also adds to the cost by introduction of an extra switch and PCB space.

Moreover, as these keyhole RESET pins can be difficult to access, a popular "fix" is to remove the battery. This can potentially damage the system, and thereby cause critical data loss. Some systems even hinder the user from removing the battery and lead him to a precarious situation.

To overcome the frustration people feel when products "freeze" in mid-operation, STMicroelectronics has developed a new IC which supports safe manual restart using regular function buttons. This would not only lower the cost of putting the reset key in the equipment, but would also avoid the risk of data loss by removing the battery.

The new STM65xx family of smart-reset Integrated Circuits (IC) has two inputs that can be connected to two of the device's normal function buttons. When these are held down for a certain time, which is programmable, the IC will send a reset signal to the main processor. The two inputs and programmable delay time allow a combination of button presses and hold-down times to guard against unintended resets.

While other ICs on the market can control one reset key, only the STM65xx has this smart-reset capability with two inputs and also includes the system-controlled supervision and reset features that most product designs require. SMART Push Button On/Off Controller is a new family of House Keeping controllers, which aims to help designers to avoid some commonly seen "push buttons and power path management" challenges. It can also help designers simplify designs, reduce parts count, and save on overall system cost while improving the device design.

Click on image to enlarge.

The arrival of this chip will enhance users' experiences by providing a safe, convenient, and easily understood means of restarting those frozen gadgets. For manufacturers, combining an improved manual reset with the system-controlled reset functions in a single chip offers better performance and saves cost and pc-board space. Its 2 x 2 mm package has a smaller overall footprint than using separate chips for system reset and one-key manual reset, or an equivalent network of discrete components that can occupy as much as 100 sq-mm on the board.

In addition, by allowing the manual reset to be controlled from the normal user buttons, the STM65xx can enable product designers to eliminate the traditional hidden reset requiring an access hole in the casing. This can save tooling costs and also provides an opportunity to create splash-resistant or waterproof products.


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