Keyboard control apparatus

#1. Field of the Invention

#The invention relates to a keyboard controller built in a core-logic chip set located in the built-in keyboard of a notebook computer to connect a keyboard encoder through a general simple connection interface and transmit keyboard matrix value to the keyboard encoder.

#2. Description of the Prior Art

#FIG. 1 is a block diagram of the circuit of a built-in keyboard of a conventional notebook computer.

#FIG. 2 is a block diagram of circuit of a built-in keyboard for a notebook computer according to the invention.

#A general typical notebook computer includes a built-in keyboard which has a built-in matrix for the keyboard layout. Data stored on the matrix are scanned by a keyboard encoder and the position of the depression also is defined to generate a code corresponding to the keyboard that has been scanned. The code is related to the pre-stored matrix value. The invention provides a novel keyboard control apparatus to download the matrix value to a programmable keyboard encoder through a series interface, and also to effectively simplify keyboard encoder design to prevent the high cost of using the micro-controller.

#Refer to FIG. 2 for the block diagram of the circuit of a built-in keyboard for a notebook computer according to the invention. The notebook computer according to the invention includes a core-logic chip set 50 which has a keyboard controller 52 and a serial bus interface 54. The core-logic chip set 50 connects to a keyboard encoder 60 which is radically different from conventional designs. In practice, the keyboard encoder 60 is a programmable encoder which may be programmed according to user's requirements. The keyboard encoder 60 includes a serial/parallel bus interface 62 which may be a general PS/2 connection interface adopted in general computers. The serial/parallel bus interface 62 connects to the keyboard controller 52 of the core-logic chip set 50 to link signals of the keyboard encoder 60 and the keyboard controller 52. It may be accomplished by simply connecting a PS/2 bus.

#The keyboard encoder 60 also includes a scan controller 68 which connects to the serial/parallel bus interface 62 to perform control of keyboard scan operations. It has an input end to input scan input signals and an output end to deliver scan output signals. The keyboard encoder 60 further includes a serial bus interface 64 connecting to the serial bus interface 54 of the core-logic chip set 50 for downloading a set of table value into the keyboard encoder 60. It may adopt a general serial bus connection such as a COM1 Port connection line used in the general computers to achieve the download transmission operation. The keyboard encoder 60 also has a matrix table 66 which contains table value. It has an input end connecting to the serial bus interface 64 and an output end connecting to the scan controller 68. The contained value in the matrix table 66 is stored in the memory, and may be stored in a pre-stored fashion. Moreover, download of the contained value of the matrix table 66 is transmitted from the core-logic chip set 50 to the keyboard encoder 60 through the serial bus.