DA

Register

Contents

Notes

0 to 7

State

Function

7

—

1

6

—

1

Command 6 identification code.

5

—

1

Sets up synchronizing signal control.

4

—

0

3

SEL0

0

1

2

MOD0

0

1

1

DISLIN

0

12 lines

Switches the number of lines displayed

1

10 lines

0

MUT

0

Normal output

1

SEL0

MOD

SEPOUT output

0

0

Sync separator signal

0

1

Low-level output

1

0

High-level output

1

1

ST pulse signal

No. 5731-15/23

LC74788, 74788M, 74788JM

COMMAND6 (Synchronizing signal detection setup command)

• First byte

• Second byte

DA

Register

Contents

Notes

0 to 7

State

Function

7

—

0

Second byte identification bit

6

RN2

0

1

5

RN1

0

1

4

RN0

0

1

3

SN3

0

1

2

SN2

0

1

1

SN1

0

1

0

SN0

0

1

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

External synchronizing signal detection control.

Signal absent

→ signal present transition detection

Sets the sampling period in which SYNC can be

detected continuously in the horizontal synchronizing

signal period (1H).

External synchronizing signal detection control.

Signal present

→ signal absent transition detection

Sets the sampling period in which SYNC cannot be

detected continuously in the horizontal synchronizing

signal period (1H).

RN2

RN1

RN0

Number of times HSYNC detected

0

0

0

0 times

0

0

1

4 times

0

1

0

8 times

1

0

0

16 times

SN3

SN2

SN1

SN0

Number of times HSYNC detected

0

0

0

0

Not detected

0

0

0

1

32 times

0

0

1

0

64 times

0

1

0

0

128 times

1

0

0

0

256 times