Broadcom

- 15 -

HDLx-2416 Series

Data Sheet

Table 1 shows how the Extended Function Disable (bit D6 of

the Control Register), Master Blank (bit D2 of the Control

Register), Digit Blank Disable (bit D1 of the Attribute RAM), and

BL input can be used to blank the display.

When the Extended Function Disable is a logic 1, the display

Function Disable is a logic 0, the display can be blanked

is logic 0 or the Master Blank is logic 1, providing all Digit Blank

Disable bits are logic 0. Those digits with Digit Blank Disable

bits a logic 1 will ignore both blank signals and remain ON. The

Digit Blank Disable bits allow individual characters to be

Dimming

input or the Control Register. A pulse width modulated signal

word in the Control Register generates an internal pulse width

modulated signal to dim the display. The internal dimming

feature is enabled only if the Extended Function Disable is a

logic 0.

Bits 3–5 in the Control Register provide internal brightness

control. These bits are interpreted as a three bit binary code,

with code (000) corresponding to the maximum brightness

and code (111) to the minimum brightness. In addition to

varying the display brightness, bits 3–5 also vary the average

value of IDD. IDD can be specified at any brightness level as

shown in Table 2.

Table 1 Display Blanking Truth Table

EFD

MB

BL

0000

Display Blanked by BL

0

0X

1

Display ON

0

X

1

0

Display blanked by PL. Individual

characters "ON" based on "1" being

0

1

0

X

Display Blanked by MB

0111

Display Blanked by MB. Individual

characters "ON" based on "1" being

1

X

X

0

Display Blanked by BL

1

X

X

1

Display ON

Table 2 Current Requirements at Different Brightness Levels

Symbol

Brightness

25°C Typ.

25°C Max.

Max. over Temp.

Unit

000100%

110

130

160

mA

00160%

66

79

98

mA

01040%

45

53

66

mA

01127%

30

37

46

mA

10017%

20

24

31

mA

10110%

12

15

20

mA

1107%

9

11

15

mA

1113%

4

6

9

mA