ST7066

V1.2

2000/6/13

13

Instructions

There are four categories of instructions that:

!" Designate ST7066 functions, such as display format, data length, etc.

!" Set internal RAM addresses

!" Perform data transfer with internal RAM

!" Others

Instruction Table:

Instruction Code

Instruction

RS RW

DB

7

DB

6

DB

5

DB

4

DB

3

DB

2

DB

1

DB

0

Description

Description

Time

(270KHZ)

Clear

Display

0

0

0

0

0

0

0

0

0

1

Write

"20H"

to

DDRAM.

and

set

DDRAM address to "00H" from AC

1.52 ms

Return

Home

0

0

0

0

0

0

0

0

1

x

Set DDRAM address to "00H" from AC

and return cursor to its original position

if shifted. The contents of DDRAM are

not changed.

1.52 ms

Entry Mode

Set

0

0

0

0

0

0

0

1

I/D

S

Sets cursor move direction and

specifies display shift. These operations

are performed during data write and

read.

37 us

Display

ON/OFF

0

0

0

0

0

0

1

D

C

B

D=1: entire display on

C=1: cursor on

B=1: cursor position on

37 us

Cursor or

Display

Shift

0

0

0

0

0

1

S/C R/L

x

x

Set cursor moving and display shift

control bit, and the direction, without

changing DDRAM data.

37 us

Function

Set

0

0

0

0

1

DL

N

F

x

x

DL: interface data is 8/4 bits

NL: number of line is 2/1

F: font size is 5x11/5x8

37 us

Set

CGRAM

address

0

0

0

1

AC

5

AC

4

AC

3

AC

2

AC

1

AC

0

Set CGRAM address in address counter

37 us

Set DDRAM

address

0

0

1

AC

6

AC

5

AC

4

AC

3

AC

2

AC

1

AC

0

Set DDRAM address in address counter

37 us

Read Busy

flag and

address

0

1

BF

AC

6

AC

5

AC

4

AC

3

AC

2

AC

1

AC

0

Whether during internal operation or not

can be known by reading BF. The

contents of address counter can also be

read.

0 us

Write data

to RAM

1

0

D7

D6

D5

D4

D3

D2

D1

D0

Write data into internal RAM

(DDRAM/CGRAM)

43 us

Read data

from RAM

1

1

D7

D6

D5

D4

D3

D2

D1

D0

Read data from internal RAM

(DDRAM/CGRAM)

43 us

Note:

Be sure the ST7066 is not in the busy state (BF = 0) before sending an instruction from the MPU to the ST7066.

If an instruction is sent without checking the busy flag, the time between the first instruction and next instruction

will take much longer than the instruction time itself. Refer to Instruction Table for the list of each instruction

execution time.