PD2435 Datasheet, PDF (8/11 Pages) OSRAM GmbH – 4-Character 5 x 7 Dot Matrix Alphanumeric Programmable Display™ with Built-in CMOS Control Functions

D7 D6 D5 D4 D3 D2 D1 D0 Operation
0 0 0 0 X X B B Disable highlight
attribute
0 0 0 1 0 0 B B Display cursor*
instead of
character
0 0 0 1 0 1 B B Blink single
character
0 0 0 1 1 0 B B Display blinking
cursor* instead
of character
0 0 0 1 1 1 B B Alternate charac-
ter with cursor*
*“Cursor”= all dots in a single character space lit to half brightness
X=Don't care
B=Depends on the selected brightness.
Attributes are non-destructive. If a character with bit D7 set is
replaced by a cursor (Control Word bit D4 is set, and D3=D2=0)
the character will remain in memory and can be revealed again
by clearing D4 in the Control Word.
Blink (D5): The entire display can be caused to blink at a rate of
approximately 2.0 Hz by setting bit D5 in the Control Word. This
blinking is independent of the state of D7 in all character locations.
To synchronize the blink rate in a bank of these devices, it is
necessary to tie all devices' clocks and resets together as
described in a later section of this data sheet.
D7 D6 D5 D4 D3 D2 D1 D0 Operation
0 0 1 X X X B B Blinking display
Lamp Test (D6): When the Lamp Test bit is set, all dots in the
entire display are lit at half brightness. When this bit is cleared,
the display returns to the characters that were showing before
the lamp test.
D7 D6 D5 D4 D3 D2 D1 D0 Operation
0 1 0 X X X X X Lamp test
Clear Data (D7): When D7 is set (D7=1) in the Control Word, all
(display) memory bits are reset to zero and the display goes blank.
D7 D6 D5 D4 D3 D2 D1 D0 Operation
1 0 X X X X X X Clear
A second control word must be written into the chip with D7
reset (D7=0) to set up attributes and brightness levels.
The SMC-4740 oscillator is designed to drive up to 16 displays
with input loading of 15 pF each.
The general requirements for cascading 16 displays are:
1. Determine the correct address for each display.
2. Tie CE0 to ground and use CE1 from an address.
3. Select one of the displays to provide the clock for the
other displays.
4. Tie CLKSEL to ground on other displays.
5. Use RST to synchronize the blinking between the displays.
Figure 6. Cascading Diagram
RST
RD
WR
VCC
WR RD RST CLK I/O CLKSEL
Programmable Display
D0-D7 A0-A2 CE0 CE1
Data I/O
Address
A4
A5
Address
Decoder ^{Address Decode Chip 1 to 14}
A6
14 More Displays
in between
WR RD RST CLK I/O CLKSEL
Programmable Display
D0-D7 A0-A2 CE0 CE1
 2001 OSRAM Opto Semiconductors Inc.• San Jose, CA
www.infineon.com/opto • 408-456-4000
OSRAM Opto Semiconductors GmbH & Co. OHG • Regensburg, Germany
www.osram-os.com • [phone]
8
PD2535/6/7, PD3535/6/7, PD4435/6/7
July 5, 2001-14