ST7920 LCD controller/driver IC can display alphabets， numbers， Chinese fonts and self-defined characters. It supports 3 kinds of bus interface， namely 8-bit， 4-bit and serial. All functions， including display RAM， Character Generation ROM， LCD display drivers and control circuits are all in a one-chip solution. With a minimum system configuration， a Chinese character display system can be easily achieved. ST7920 includes character ROM with 8192 16x16 dots Chinese fonts and 126 16x8 dots half-width alphanumerical fonts. Besides， it supports 64x256 dots graphic display area for graphic display （GDRAM）。 Mix-mode display with both character and graphic data is possible. ST7920 has built-in CGRAM and provide 4 sets software programmable 16x16 fonts. ST7920 has wide operating voltage range （2.7V to 5.5V）。 It also has low power consumption. So ST7920 is suitable for battery-powered portable device. ST7920 LCD driver consists of 32-common and 64-segment. Company with the extension segment driver （ST7921） ST7920 can support up to 32-common x 256-segment display