LC7982A Datasheet, PDF (9/18 Pages) Sanyo Semicon Device – LCD Dot Matrix Graphics Display Controller

LC7982A
Display Control Instructions
The display is controlled by writing data to the instruction register and the 13 data registers. The instruction register and
the data registers are differentiated using the RS signal. First, with RS set to 1 the application writes 8-bit data to the
instruction register and specifies the code for the data register. Then, with RS set to 0, the application writes 8-bit data to
the data register, and the specified instruction is executed. Note that another instruction cannot be written while the
previous instruction is executing. Since the busy flag is set during this period, applications must verify that the busy flag
is 0 before writing an instruction. However, after a data read instruction or a data write instruction, the microcontroller
may execute the next instruction without checking the busy flag after the maximum value of the read cycle or write cycle
elapses, respectively
• Mode control
Applications specify the mode control register by writing 00H to the instruction register.
(The form "00H" is used to express values in hexadecimal.)
Register
Instruction register
Mode control register
R/W RS
01
00
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
00000000
00
Mode data
DB5 DB4 DB3 DB2 DB1 DB0
Cursor/blinking
CG Graphics/character display
00
Cursor off
01
10
Cursor on
0
Cursor off/character blinking
11
0
1/0 1/0 0 0
Cursor blinking
Cursor off
Character display
mode
01
10
Cursor on
1
Cursor off/character blinking
11
Cursor blinking
0010
Graphics mode
Display
on/of
Master/
slave
Blinking
Cursor
Mode
Internal/
external
CG
1: Master mode
0: Slave mode
1: Display on
0: Display off
• Character pitch setting
Register
Instruction register
Character pitch register
R/W RS
01
00
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
00000001
(VP - 1) binary
0 (HP - 1) binary
VP indicates the number of dots in the vertical direction per character. Applications should determine this value based
on the desired vertical separation between characters. This setting is only meaningful in character display mode, and is
ignored in graphics mode.
In character display mode, HP indicates the number of dots in the horizontal direction per character, and also includes
the gap between the current character and the character displayed to the right. In graphics mode, HP indicates the
number of bits displayed from each byte of display data from RAM.
HP can be set to one of three values.
Hp DB2 DB1 DB0
6101
7110
8111
Setting
Horizontal character pitch of 6 dots
Horizontal character pitch of 7 dots
Horizontal character pitch of 8 dots
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