2–140

PLCD5580/1/2/3/4

Control Word Format

Display Brightness

The display can be programmed to vary between blank, 13%, 20%, 27%, 40%, 53%, 80%, and

full brightness. Bits D0, D1 and D2 control the display brightness.

X= Don’t care

Flash RAM Function

Character Flash is controlled by FL pin, bit D0 and control word bit D3. Combination

of FL being low, proper digit address and D0 being high will write a flash bit into the

Flash RAM Register. In the control word mode when D3 is brought high, the above

mentioned character will flash.

Setting the Flash Bit

X=Don’t care A=Selected address

Character Flash Control Word

X=Don’t care B=Selected brightness

Display Blinking

Blinking function is independent of Flash function. When D4 is held high, entire display blinks at 2 Hz.

X=Don’t care B=Selected brightness

Lamp Test

Bit D6 when brought high will cause all the LEDs in all eight digits to light up at 53% brightness.

Selecting or de-selecting Lamp Test has no effect on the display memory.

X=Don’t care

CE

WR

FL

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

Display Brightness

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

1

1

1

1

1

0

0

0

0

0

0

0

0

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

0

0

0

0

1

1

1

1

0

0

1

1

0

0

1

1

0

1

0

1

0

1

0

1

100% Brightness

80% Brightness

53% Brightness

40% Brightness

27% Brightness

20% Brightness

13% Brightness

Blank Display

CE

WR

FL

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

Operation

0

0

0

0

0

0

X

X

A

A

A

A

A

A

X

X

X

X

X

X

X

X

X

X

X

X

X

X

0

1

Flash RAM disabled

Flash RAM enabled

CE

WR

FL

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

Operation

0

0

0

0

1

1

0

0

X

X

X

X

X

X

0

0

0

0

X

X

0

0

0

1

B

B

B

B

B

B

Disable Flashing Char.

Enabled Flashing Char.

CE

WR

FL

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

Operation

0

0

0

0

1

1

0

0

X

X

X

X

X

X

0

0

0

0

X

X

0

1

0

0

B

B

B

B

B

B

Display Blinking disabled

Display Blinking enabled

CE

WR

FL

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

Operation

0

0

0

0

1

1

0

0

X

X

X

X

X

X

0

0

0

0

X

X

0

0

X

0

X

X

X

X

X

X

Lamp Test disabled

Lamp Test enabled