User manual for ST7920 controller series LCD modules, describing the hardware and software features of the products.
This manual describes the ST7920 controller series LCD modules, including their main features, hardware layout, and built‑in font resources. It covers the parallel and serial interface options, power‑up reset, internal oscillator, and the various RAM areas for characters, icons and graphics.
Detailed sections explain the pin functions, voltage levels, contrast adjustment methods, and provide schematic diagrams for each module variant. The document also lists electrical characteristics such as input/output levels and current consumption, helping designers integrate the module into their systems. This manual is written in Chinese.
| Interface options | 8‑bit, 4‑bit parallel and serial optional |
|---|---|
| COM and SEG outputs | 33 COM lines, 64 SEG lines |
| Maximum LCD resolution | 236 × 32 dots (with ST7921 driver) |
| DDRAM size | 64 × 16 bits (up to 16 characters × 4 lines) |
| Chinese character ROM | 2 M‑bit CGROM, 8192 characters (16 × 16) |
| Western character ROM | 126 characters (16 × 8) |
| Icon RAM | 240‑point ICON RAM (15 × 16) |
| Internal oscillator | Built‑in oscillator |
Set the PSB pin high for parallel mode or low for serial mode; the module may have a jumper or require external handling.
ST7920‑0A includes a BIG‑5 traditional Chinese font, while ST7920‑0B provides a simplified Chinese (0B code) font.
The module is powered from a 5 V VCC line; VEE is optional for LCD drive voltage, and V0 is used for contrast control.