COP472MW-3 National Semiconductor, COP472MW-3 Datasheet - Page 5
![no-image](/images/manufacturer_photos/0/4/469/national_semiconductor_sml.jpg)
COP472MW-3
Manufacturer Part Number
COP472MW-3
Description
COP472-3 Liquid Crystal Display Controller
Manufacturer
National Semiconductor
Datasheet
1.COP472MW-3.pdf
(8 pages)
Functional Description
The COP472-3 drives 36 bits of display information orga-
nized as twelve segments and three backplanes The
COP472-3 requires 40 information bits 36 data and 4 con-
trol The function of each control bit is described below
Display information format is a function of the LCD intercon-
nections A typical segment backplane configuration is illus-
trated in Figure 5 with this configuration the COP472-3 will
drive 4 digits of 9 segments
To adapt the COP472-3 to any LCD display configuration
the segment backplane multiplex scheme is illustrated in
Table I
Two or more COP472-3 chips can be cascaded to drive
additional segments There is no limit to the number of
COP472-3’s that can be used as long as the output loading
capacitance does not exceed specification
Bit Number
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
1
2
3
4
5
6
7
8
9
TABLE I COP472-3 Segment Backplane
Backplane
Segment
SA1 BPC
SC1 BPA
SC1 BPB
SB1 BPC
SA2 BPC
SC2 BPA
SC2 BPB
SB2 BPC
SA3 BPC
SC3 BPA
SC3 BPB
SB3 BPC
SA4 BPC
SC4 BPA
SC4 BPB
SB4 BPC
SC1 BPC
SC2 BPC
SC3 BPC
SC4 BPC
SB1 BPB
SA1 BPB
SA1 BPA
SB1 BPA
SB2 BPB
SA2 BPB
SA2 BPA
SB2 BPA
SB3 BPB
SA3 BPB
SA3 BPA
SB3 BPA
SB4 BPB
SA4 BPB
SA4 BPA
SB4 BPA
not used
Multiplex Scheme
SYNC
Q6
Q7
SH
SG
SF
SE
SD
SC
SB
SA
SH
SG
SF
SE
SD
SC
SB
SA
SH
SG
SF
SE
SD
SC
SB
SA
SH
SG
SF
SE
SD
SC
SB
SA
SPA
SP2
SP3
SP4
Numeric Display
Data to
Digit 1
Digit 2
Digit 3
Digit 4
Digit 1
Digit 2
Digit 3
Digit 4
5
SEGMENT DATA BITS
Data is loaded in serially in sets of eight bits Each set of
segment data is in the following format
Data is shifted into an eight bit shift register The first bit of
the data is for segment H digit 1 The eighth bit is segment
A digit 1 A set of eight bits is shifted in and then loaded into
the digit one latches The second set of 8 bits is loaded into
digit two latches The third set into digit three latches and
the fourth set is loaded into digit four latches
CONTROL BITS
The fifth set of 8 data bits contains special segment data
and control data in the following format
The first four bits shifted in contain the special character
segment data The fifth bit is not used The sixth and sev-
enth bits program the COP472-3 as a stand alone LCD driv-
er or as a master or slave for cascading COP472-3’s BPC
of the master is connected to BPA of each slave The fol-
lowing table summarizes the function of bits six and seven
The eighth bit is used to synchronize two COP472-3’s to
drive an 8 -digit display
SYNC
SA
Q7
1
0
1
0
Q6
1
1
0
0
SB
Q7
Slave
Stand Alone
Not Used
Master
Function
SC
Q6
SD
X
BPC Output
Backplane
Output
Backplane
Output
Internal
Osc Output
Internal
Osc Output
SP4
SE
SP3
SF
http
BPA Output
Oscillator
Input
Backplane
Output
Oscillator
Input
Backplane
Output
SP2
SG
www national com
SP1
SH