http://www.crystalfontz.com

email: sales@crystalfontz.com

Phone: (509) 291-3514

Fax:

(509) 291-3345

Crystalfontz America, Inc.

15611 East Washington Road

Valleyford, WA 99036

Display Data RAM (DDRAM)

This DDRAM is used to store the display data represented in 8-bit character codes. Its extended

capacity is 80

8 bits or 80 characters. Below figure is the relationships between DDRAM

addresses and positions on the liquid crystal display.

Character Generator ROM (CGROM)

The CGROM generate 5

8 dot or 510 dot character patterns from 8-bit character codes. See

Table 2.

Character Generator RAM (CGRAM)

In CGRAM, the user can rewrite character by program.

For 5

8 dots, eight character patterns

can be written, and for 5

10 dots, four character patterns can be written.

Write into DDRAM the character code at the addresses shown as the left column of table 1. To

show the character patterns stored in CGRAM.

AC

(hexadecimal)

High bits

Low bits

AC6 AC5 AC4 AC3 AC2 AC1 AC0

1

0

0

1

1

1

0

Example: DDRAM addresses 4E

Display position DDRAM address

00

01

02

03

04

05

06

07

08

09 0A 0B 0C 0D 0E

0F

40

41

42

43

44

45

46

47

48

49 4A 4B 4C 4D 4E

4F

2-Line by 16-Character Display

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16