Patent ID: 8115747

Claim:
An energy-efficient touch panel control device comprising: a touch panel comprising a plurality of horizontal traces and a plurality of vertical traces, corresponding to a plurality of capacitive load parameters, for generating a plurality of analog output voltages; a buffer memory for storing digital trace data; an interrupt initiation unit, for counting a number of digital trace data stored in the buffer memory, and outputting an interrupt signal when the number of digital trace data stored in the buffer memory is greater than or equal to a predefined value; an analog to digital conversion unit, coupled to the touch panel and the buffer memory, for converting the plurality of analog output voltages to a plurality of digital trace data and storing the plurality of digital trace data in the buffer memory, and switching an operating mode according to a first control signal; an operation unit, coupled to the buffer memory, for generating a detection result according to the plurality of digital trace data read from the buffer memory, and switching the operating mode according to a second control signal; a mode control unit, coupled to the interrupt initiation unit, the operation unit and the analog to digital conversion unit, for generating the first control signal for the analog to digital conversion unit, and the second control signal for the operation unit according to the interrupt signal; and a host interface unit, coupled to the operation unit, for transmitting a touch event message to a computer host according to the detection result; wherein the mode control unit is utilized for generating the first and second control signals according to the interrupt signal such that the analog to digital conversion unit is operated in a sleep mode and the operation unit is operated in an active mode; and wherein the mode control unit is utilized for generating the first and second control signals after the operating unit completes the generating a detection result such that the analog to digital conversion unit is operated in an active mode and the operation unit is operated in a sleep mode.