Depending on the muxing used, multiple Sx pins are required to display an entire digit or character on the screen. Which display areas are muxed together depends on the particular LCD glass and how the LCD has mapped these segments to drive pins. Choosing the right LCD display makes software less complex. For example, if a display has the Sx pins mapped to segments that allow the segment to display any numerical digit using only one or two Sx pins, the code is easier to write. The mapping of pins to LCD segments is found in the LCD data sheet.

Figure 5-1 shows some information from the data sheet for the LCD glass on the LP-MSPM0L2228 Launchpad Development Kit, which has a 4-mux display. This display allows for showing alphanumeric characters in addition to simple digits. The pin mapping found in the display data sheet, shows that the segments required to display any digit 0-9 require two Sx pins – pin 1 and 2 of the LCD. To display any alphabet character, use 4 segment pins.

Figure 5-1 4-Mux Display Data Sheet Example

In addition to the mapping of the LCD glass, careful selection of which Sx segment pins on the MSPM0 to connect to which LCD segment pins on the LCD glass has a big impact on layout and software.