
SCDV5540, SCDV5541, SCDV5542, SCDV5543, SCDV5544
2006-01-23
9
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 Character Address and
Loading Column Data are shown in Tables Load Character
The user can select seven specific LED brightness levels, Table
Display Brightness“ (page 9). These brightness levels (in percent-
ages of full brightness of the display) include: 100% (F0
HEX), 53%
(F1
HEX), 40% (F2HEX), 27% (F3HEX), 20% (F4HEX), 13% (F5HEX),
and 6.6% (F6
HEX). The brightness levels are controlled by chang-
ing the duty factor of the row strobe pulse.
Row and Column Location
The SCDV554X offers a unique Display Power Down feature which
reduces I
CC to less than 50 A. When FFHEX is loaded, as shown in
Table Power Down“ (page 9), 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 display is
reactivated by loading a new Brightness Level Control Word into
the display.
The Lamp Test is enabled by loading F8
HEX, Table Lamp Test“
(page 9), into the 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.
The Software Clear (C0
HEX), given in Table Software Clear“
(page 9), clears the Address Register and the RAM. The display is
blanked and the Character Address Register will be set to Charac-
ter 0. The internal counter and the Control Word Register are unaf-
fected. The Software Clear will remain active until the next data
input cycle is initiated.
Load Character Address
Op code
D7 D6 D5
Character Address
D4 D3
D2
D1
D0
Hex
Operation
Load
10
1
00
0
A0
Character 0
10
1
00
0
1
A1
Character 1
10
1
00
0
1
0
A2
Character 2
10
1
00
0
1
A3
Character 3
Load Column Data
Op code
D7 D6 D5
Column Data
D4 D3
D2
D1
D0
Operation Load
00
0
C0 C1
C2
C3
C4
Row 0
00
1
C0 C1
C2
C3
C4
Row 1
01
0
C0 C1
C2
C3
C4
Row 2
01
1
C0 C1
C2
C3
C4
Row 3
10
0
C0 C1
C2
C3
C4
Row 4
IDXX5185
Row 0
Row 1
Row 2
Row 3
Row 4
01
2
3
4
Previously "on" LED
On LED
Off LED
Columns
Display Brightness
Op code
D7 D6 D5
Control Word
D4 D3
D2
D1
D0
Hex
Operation
Level
11
1
10
0
F0
100%
11
1
10
0
1
F1
53%
11
1
10
0
1
0
F2
40%
11
1
10
0
1
F3
27%
11
1
10
1
0
F4
20%
11
1
10
1
0
1
F5
13%
11
1
10
1
0
F6
6.6%
Power Down
Op code
D7 D6 D5
Control Word
D4 D3
D2
D1
D0
Hex
Operation
Level
11
1
11
1
FF
0%
brightness
Lamp Test
Op code
D7 D6 D5
Control Word
D4 D3
D2
D1
D0
Hex
Operation
Level
11
1
10
B
Lamp Test
(OFF)
11
1
11
0
F8
Lamp Test
(OFF)
Software Clear
Op code
D7 D6 D5
Control Word
D4 D3
D2
D1
D0
Hex
Operation
Level
11
0
00
0
C0
CLEAR