Segmented LCDs use multiplexing (muxing) to limit control pin count. Types of displays include static (no muxing) and 2 through 8-mux. The notation N-mux means each segment pin Sx drives N segments on the display – this also means there are N common (COMx) pins. Each LCD segment on the display is driven by the combination of a COMx pin and Sx pin, providing a difference in potential across the liquid crystals for that segment.

Muxing allows a limited number of pins to control a larger number of segments. If there is an 8-mux LCD display, then there are 8 COM pins and each segment (Sx) pin drives 8 segments. So when using an 8-mux capable MSPM0 with 51 Sx pins available (S0-S50), then MSPM0 is able to control 408 segments with only 8 (COMx) + 51 (Sx) = 59 pins.

MSPM0 devices with 8-mux mode support up to 408 segment displays. However, make sure to check the device-specific data sheet to see how many segments the particular device supports, the number of supported segments is limited not only by the muxing capability of the LCD module, but also by the number of LCD pins available on the particular device in a particular pin-package.

Figure 4-1 MUX Configurations