2–8

SCD5580/5581/5582/5583/5584

The user can activate four Control functions. These include:

LED Brightness Level, Lamp Test, IC Power Down, or Display

Clear. OPCODEs and five bit words are used to initiate these

functions. The OPCODEs and Control Words for the Charac-

ter Address and Loading Column Data are shown in Tables 2

and 3.

Table 2. Load character address

Table 3. Load column data

Figure 10. Row and column location

Opcode

Character Address

Operation

Load

D7

D6

D5

D4

D3

D2

D1

D0

10100000A0

Character 0

10100001A1

Character 1

10100010A2

Character 2

10100011A3

Character 3

10100100A4

Character 4

10100101A5

Character 5

10100110A6

Character 6

10100111A7

Character 7

Opcode

Column Data

Operation Load

D7

D6

D5

D4

D3

D2

D1

D0

000C0

C1

C2

C3

C4

Row 0

001C0

C1

C2

C3

C4

Row 1

010C0

C1

C2

C3

C4

Row 2

011C0

C1

C2

C3

C4

Row 3

100C0

C1

C2

C3

C4

Row 4

off LED

on LED

Row 0

Row 1

Row 2

Row 3

Row 4

0 1 2 3 4

Columns

Previously “on” LED

The user can select seven specific LED brightness levels,

Table 4. These brightness levels (in percentages of full bright-

ing the duty factor of the row strobe pulse.

Table 4. Display brightness

The SCD558X offers a unique Display Power Down feature

as shown in Table 5, the display is set to 0% brightness and

the internal multiplex clock is stopped. When in the Power

Down mode data may still be written into the RAM. The dis-

play is reactivated by loading a new Brightness Level Control

Word into the display.

Table 5. Power down

serial shift register. This Control Word sets all of the LEDs to a

53% brightness level. Operation of the Lamp Test has no

affect on the RAM and is cleared by loading a Brightness

Control Word.

Opcode

Control Word

Hex

Operation

Level

D7

D6

D5

D4

D3

D2

D1

D0

11110000F0

100%

11110001F1

53%

11110010F2

40%

11110011F3

27%

11110100A4

20%

11110101F5

13%

11110110F6

6.6%

Opcode

Control Word

Hex Operation

D7

D6

D5

D4

D3

D2

D1

D0

11111111FF

0%

brightness

Figure 11. Row strobing

Row 0

Row 1

Row 2

Row 3

Row 4

0 1 2 3 4

Columns

Row 0

Row 1

Row 2

Row 3

Row 4

0 1 2 3 4

Columns

Row 0

Row 1

Row 2

Row 3

Row 4

0 1 2 3 4

Columns

Row 0

Row 1

Row 2

Row 3

Row 4

0 1 2 3 4

Columns

Row 0

Row 1

Row 2

Row 3

Row 4

0 1 2 3 4

Columns

ROW LOAD

LOAD ROW 0

LOAD ROW 1

LOAD ROW 2

LOAD ROW 3

LOAD ROW 4