The DCM-20434 LCD display is interfaced to the MCU’s SPI-0 serial port through a serial to parallel converter as shown in Figure 3. Figure 3 shows the interface connections between the SPI-0 serial port, the 74HC595 (serial to parallel converter) device, and the LCD-PORT. The DCM-20434 LCD should be configured in four bit mode as the schematic shows DB3 through DB0 connected to ground. This is the interface figure.
To interface the LCD display to the HCS12 MCU you must understand how the physical layer interface circuit is constructed (shown in Schematics for Development Board), how to configure and use the SPI serial port (SPI Serial Bus Document), and how to configure and use the LCD display (DMC-20434 LCD Specifications ).