Legerity, Inc.

Kenneth Tallo

Paul G Schnizlein

Kenneth D Alton

The invention is, in its various aspects, an apparatus and a method for scanning a keypad or a keyboard. The apparatus comprises a keypad and an integrated circuit. The keypad includes a plurality of chained resistors and a plurality of key switches. Each of the plurality of key switches is tied to a common node at a first terminal thereof and tapping the chained resistors at a second node thereof. Each of the key switches generates a signal indicative of the respective key switch being pressed when the key switch is pressed. The integrated circuit is capable of receiving the generated signal. The integrated circuit furthermore includes an analog to digital converter capable of generating a reference signal and a circuit capable of determining which key switch has been pressed from the magnitude of the generated voltage signal and the reference signal. The method for scanning a keypad comprises generating a voltage signal whose magnitude indicates which key is being pressed, and determining from the magnitude of the generated voltage signal which key was pressed.

Keypad scanning with few pins

A method and apparatus for allowing developers to develop software for their product. The method includes providing a first mode signal to a processor to operate in a development mode. The method also includes executing instructions stored in a first region of the memory in response to the first mode signal, providing data to the processor, and writing the data into a second region of the memory.

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Austin, TX, United States of America

Kenneth Tallo