Research Of Temperature Displaying System Based On CPLD

Method of designing LCD driver and controller with CPLD chip is introduced in this dissertation, including drive circuits, interface circuits, and software design. The designing procedure is also described by using VHDL hardware description language. Realizing all needed function such as encoding, sequence control, display control and so on with only two CPLD chips, it can be used to control the display of LCD. On the basis of description on features of LCD plate display, the design method of hardware and software of intelligent embedded LCD displaying system is discussed. This dissertation also gives the hardware and software of this system in detail, and then realizes by using programmable logic device MAX7000S series. The application of CPLD in this logic design, simply the hardware, and enable ease of the LCD to use portably.To display, the LCD needs not only driver voltage from the driver, but also displaying data and control signals from the controller. The controller was be controlled by PC, and also can work independently. We choose AT89C51 as MPU of this system, the CPLD is EPM7256S, and the LCD is TFT with 320*240 pixels.This design is begin from the technology parameter of LCD. By studying of the drive system, we get the graph of the drive system. The whole drive system is formed by a driver and it's periphery circuits. The driver include BUS holder, data decoder, display RAM, and LCD scanning circuits. We also adding CFFL, temperature compensate circuit, and DC-DC into our design.The connection of periphery circuits, and the codes of programs and graphs is included in this dissertation. The designed displaying system fits the project well.