What Is A LCD Character Map Or Character Generator?

What makes the character LCD so easy to program is the built-in LCD character map located on the controller/driver chip.

When designing a new product, most engineers want to incorporate a LCD technology that is easy to program, is low cost and in stock. This is why character LCD displays are one of the most popular display technologies that Focus offers.

What is a LCD character map?

The LCD character map is a table of information (memory locations) located on the controller. The map assigns a number between 0 and 255 to each letter, number and punctuation mark. When you want your customer to see a capital A, you send it number 64 and if you want it to display an 8 you send it a 122. You get the idea. This saves the engineer much time by not having to program each segment (dot), and his/her time can be better used to make coffee and check last night’s Powerball numbers.

Most character LCDs have an 8 bit parallel interface that is numbered between DB0 (Data bit 0) to DB7 (Data bit 7). The numbers in the column of the character map are for DB0 to DB3. The numbers in each row of the character map are for DB4 to DB7. (See table below)

Below is an example of a LCD character map (aka: character generator) for the English language.

Note: We are able to build character LCDs with a SPI or I2C interface, but they may not be in stock. All standard 8 bit parallel character LCDs are in stock and can be purchased immediately.

Note: There are character maps for other languages including German, French, and Spanish etc.

LCDs with a Chinese font?

It is possible to build a character LCD to display Chinese fonts. The difference between English fonts and Chinese fonts is the number of dots per character.

Each character is made up of dots. English characters normally contain five dots across and seven dots up (5×7), or seven dots across and nine dots up (7×9).

Chinese characters require sixteen dots across and sixteen dots up (16×16).

Focus Displays does not carry Chinese Font LCDs in stock, but we can build one to meet the size you need.

What is a controller/Driver?

The controller/driver is located on the back of most LCD display technology including: Character, Graphics, TFT, OLED and some FSC.

It is a small processor that converts a customer’s software (firmware) to signals that the LCD can read. The controller can be seen on the back side of the LCD. Little dabs of black tar are used to protect the controller/drivers.

Need help with your LCD design and don’t know where to start? Make a cup of coffee and then contact FocusLCDs at 480-503-4295.