Conclusion
play. Slight timing differences may be encountered for various
microprocessors, but can be resolved using similar methods as
those used when using interfacing microprocessors with various
RAMs. The techniques used in the examples were shown for
their generality. The user will undoubtedly invent other schemes
to optimize his particular system to its requirements.
Note that although other manufacturers’ products are used in
the examples, this application note does not imply specific
endorsement, or warranty of other manufacturer's products by
OSRAM. The interface schemes shown demonstrate the sim-
plicity of using the DLO4135/DLG4137 dot matrix Intelligent Dis-
Program Listing
1
; BY DAN WATSON
2
3
; TO DO LAMP TEST, SET 100% BRIGHTNESS
; AND WRITE ‘SIEMENS*’
4
5
6
7
; P3.0 = BLO\
; P3.1 = BL1\
; P3.2 = LT\
8
; P3.6 = WR\
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
; RO = DIGIT ADDRESS ( CHIP ENABLES – CE\ )
; R1 = DIGIT COUNTER
; R7 = R6 = R5 = WAIT REGISTERS
0000
0000
0003
0006
0009
000C
000F
0010
0011
0013
0015
0017
001A
001B
001C
001D
001E
001F
0021
0022
0024
0024
0024
0026
0027
0029
002A
002C
002D
002F
0030
0032
0033
0035
0036
.ORG 00H
02 00 03
12 00 24
75 B0 00
12 00 24
75 B0 07
00
INIT:JMP BEGIN
BEGIN:CALL WAIT1
MOV P3,#00H
CALL WAIT1
MOV P3,#07H
NOP
; DELAY FOR uC TO STABILIZE
; LAMP TEST
; DISPLAY LT\ FOR A WHILE
; SET ALL 8 DISPLAYS TO 100% BRT
00
NOP
78 00
79 08
74 00
90 00 37
93
F2
A3
08
E4
MOV R0,#00H
MOV R1,#08H
MOV A,#00H
MOV DPTR,#TEXT
WRT:MOVC A,@A+DPTR
MOVX @R0,A
INC DPTR
; DIGIT 7 ADDRESS
; 8 DIGIT COUNTER
; CLEAR ACC.
; ADDRESS OF THE MESSAGE
; LOAD FIRST CHAR. INTO THE ACC.
; DIGIT ADDRESS AND DATA WRITE
; NEXT CHARACTER ADDRESS
; NEXT DIGIT (6) ADDRESS
INC R0
CLR A
D9 F9
00
01 21
DJNZ R1,WRT
GO:NOP
; WRITE ALL 8 CHAR.
JMP GO
; MESSAGE ALWAYS ON
7F 88
00
7E FF
00
7D FF
00
DD FE
00
DE F8
00
DF F2
00
WAIT1:MOV R7,#88H
; DELAY LOOPS
NOP
WAIT2:MOV R6,#FFH
NOP
WAIT3:MOV R5,#FFH
NOP
DJNZ R5,$
NOP
DJNZ R6,WAIT3
NOP
DJNZ R7,WAIT2
NOP
RET
22
0037
003C
003F
003F
53 49 45 4D 45
4E 53 2A
TEXT:DB ‘SIEMENS*’
51
52
.END
2000 Infineon Technologies Corp. • Optoelectronics Division • San Jose, CA
www.infineon.com/opto • 1-888-Infineon (1-888-463-4636)
OSRAM Opto Semiconductors GmbH & Co. OHG • Regensburg, Germany
www.osram-os.com • +49-941-202-7178
Appnote 28
4
May 31, 2000-13