SPI uses four wires—MOSI, MISO, SCK, and SS—needing more pins. I2C needs only two wires, SDA and SCL, saving space.

In 4-bit mode, the LCD uses four data lines to send data in two parts, saving pins but taking more time. In 8-bit mode, it uses eight data lines to send data all at once, speeding things up but needing more pins.

Most character LCDs use the Hitachi HD44780 or compatible clones like AIP31066 or SPLC780. These share a standard 14/16-pin layout for easy wiring.

A phase-locked loop (PLL) is an electronic feedback circuit that locks an output clock to a reference signal.

LCD power consumption in an embedded system can be reduced by turning the screen off when possible and dimming the backlight.

In automotive systems, a microcontroller handles CAN or LIN bus integration with LCD modules by acting as a bus node.

Crosstalk in LCDs occurs when signals interfere between adjacent pixels, leading to ghosting or ​blurring​. 

Multiplexing in LCDs reduces pin count to simplify hardware design. It lowers manufacturing costs for small and medium size LCDs.

DMA enables direct memory access to move frame buffer data to LCD modules without CPU involvement. This speeds up display updates for embedded systems.

Developers create a dedicated LCD update task to manage graphic LCD module rendering. This task uses xTaskCreate for real-time operating systems.