No. 5731-11/23

LC74788, 74788M, 74788JM

COMMAND2: Vertical display start position and vertical character size setup command

• First byte

DA

Register

Contents

Notes

0 to 7

State

Function

7

—

1

6

—

0

Command 2 identification code

5

—

1

Sets the vertical display start position and the vertical character size

4

—

0

3

VS21

0

1

Second line vertical character size

2

VS20

0

1

1

VS11

0

1

First line vertical character size

0

VS10

0

1

VS20

0

1

VS21

0

1H/dot

2H/dot

1

3H/dot

1H/dot

The vertical display start position is set by the 6 bits

VP0 to VP5.

The weight of bit 1 is 2H.

• Second byte

DA

Register

Contents

Notes

0 to 7

State

Function

7

—

0

Second byte identification bit

6

0

Crystal oscillator frequency: 2fsc

1

Crystal oscillator frequency: 4fsc

5

VP5

0

If VS is the vertical display start position then:

(MSB)

1

VS =

4

VP4

0

H: the horizontal synchronization pulse period

1

α = 20 H (in 525-line systems)

3

VP3

0

= 25 H (in 625-line systems)

1

2

VP2

0

1

1

VP1

0

1

0

VP0

0

(LSB)

1

Note: All registers are set to 0 when the LC74788/M/JM is reset by the RST pin.

5

n=0

VS10

0

1

VS11

0

1H/dot

2H/dot

1

3H/dot

1H/dot

Character

display area