Microelectronics

The Delphi Keyboard Display Driver (KDD) is a custom IC which is capable of driving a Vacuum Fluorescent display of up to 17 segments. Three grid outputs are provided to support both duplex- and triplex-mode VF tubes. A scanning keyboard decoder allows detection of both pushbutton and rotary encoder activations. Currently two rotary encoders and 16 pushbutton switches can be accommodated. For the rotary encoders, both the direction and the amount of rotation are provided. Segment display information and keyboard switch activations are communicated to an external processor via a bi-directional low-speed serial port. An on-chip oscillator generates the necessary timing to perform full range digital dimming of the display. A default display is used to alert the user in the event of port communication loss.