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The Design of a Complete Segmented Display Unit for Arabic
Alphanumeric Characters
MOHAMMAD OSIUR RAHMAN
1
, MUBASHSHARUL ISLAM SHAFIQUE
2
,
EDGAR SCAVINO
3
, HASSAN BASRI
3
1
Department of Computer Science and Engineering
University of Chittagong, Chittagong-4331
BANGLADESH
2
Jodrey School of Computer Science
Acadia University, NS, B4P 2R6
CANADA
3
Faculty of Engineering
Universiti Kebangsaan Malaysia
MALAYSIA
Abstract: - There are four forms for most of the Arabic characters- initial, medial, final and isolated. This paper
presents the design of a complete display unit for Arabic alphanumeric characters. The word ‘complete’ signifies that
the proposed display unit can represent all forms of entire Arabic alphabets as well as Arabic numerals. The first
segmented display unit for Arabic characters in the world covered only the isolated form and did not follow any base
line to display a sequence of characters. This work extends the capability to represent all the forms of Arabic
characters and follows a base line to represent a sequence of characters. Here a grid structure of 25 non-overlapping
segments has been discovered. There can be 109 alphanumeric characters (at least 99 characters such as isolated form-
30, final form-29, medial form- 21, initial form- 20; and 10 numerals) to be displayed and 7-bit input is used to
represent each character. After analyzing appropriate segments to be activated for every character, respective logic
functions of all segments have been derived to display the entire set of Arabic alphanumeric characters.
Key-Words: - Display Unit, Dot Matrices, Karnaugh map, LED (Light Emitting Diode), 7-Segment display.
1 Introduction
Segmented representation is used in lieu of the dot
matrices representation for alphanumeric characters of
different languages. Due to concerns of cost, power loss
and design complexity, the segmented representation
becomes more popular over the dot matrices. There are
many display units for English and Bangla alphanumeric
characters. There are three common formats of LED
displays for English. For displaying only numerals and
hexadecimal letters, simple 7-segment displays [1, 2] are
used. To display numbers and the entire alphabetic, 18-
segments display [1, 2] or 5×7 dot-matrix displays [1, 2]
can be used. 26-segment [3], and 31-segment [4, 5]
models are proposed for Bengali Alphabetic characters,
Bengali characters, and Bengali composite letters
respectively. For Arabic, there are three segmented
display units only for numerals shown in [6, 7] and the
first 18-segment display unit only for the initial form of
Arabic characters is proposed in [8]. No complete
segmented display has been developed so far for Arabic
alphanumeric characters.
At present, Arabic alphabetic characters are represented
by using dot matrices, so the cost of the display unit
increases due to the storage space, the large number of
dots, the power loss and design complexity [3-8]. In this
proposed segmented display system only 25 segments
are used, which saves considerable amount of storage
space and production costs.
2 Design Philosophy of the Proposed
Arabic Display Unit
There are 30 characters (including Lam-Alif) and 10
numerals in Arabic language. Writing in Arabic is
unicase, i.e., it does not have the concepts of upper and
lower case letters but the shape of these letters change as
a function of their usage. Based on the context, a basic
character can have up to four different forms: initial,
medial, final and isolated [9].
Motivation for the proposed 25-segment display unit
came from the 18-segment display proposed by Rahman
et al. [8], which is shown in Fig.1(a). But this grid
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ISBN: 978-960-6766-67-1
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ISSN: 1790-2769
structure supports only the isolated form of the Arabic
characters and numerals. Hence, it cannot be used to
display initial, medial or final forms of the Arabic
characters. Besides, it lacks a common base line for all
characters. As a result, it creates vertical displacement
between successive characters if we try to display a
sequence of isolated characters.
After modification to the previous 18-segment grid
structure, we propose a new grid structure consisting of
25 segments shown in Figure 1(b). For simplicity
reasons, each of the 25 segments is referred to by means
of a letter of the Roman alphabet. Every form of all
Arabic characters and numerals can be displayed by
using this new grid structure. Characters generated from
this display unit strictly maintain common base line. So,
using this unit we can construct Arabic words, which so
far was impossible by the previous 18-segment display.
There can be 109 distinct alphanumeric character shapes
(10 numerals and at least 99 character shapes such as
isolated form- 30, final form-29, medial form- 21, initial
form- 20) to be displayed and so 7-bit input is used to
run the driving circuit. Individual pattern of this input
corresponds to a unique character form and activates
necessary segment(s) for displaying it (Fig.2). After
analyzing which segments will be activated for which
character, appropriate logic function for each segment
has been derived in order to represent each Arabic
alphanumeric character.
3 Methodology of Characterization for
Arabic Characters
Display quality, power consumption, cost of design
complexity, memory usage and applicability are the
most decisive factors for designing any display unit [10].
Display quality of the alphanumeric characters means
basic shape and beauty of the individual character,
which is the main concern for any display unit because
low display quality leads to damages and user rejection.
At the same time, the number of segments has direct
impact on power consumption and cost of memory and
design complexity. Thus to design this display unit, we
have used minimum number of segments while ensuring
the unique shape and beauty of all 109 characters. As
writing in Arabic is cursive, we have used four different
techniques for four forms of Arabic characters.
For the isolated form, it has been observed that some
characters can be represented in various ways by using
different combinations of segments. We used a
minimum number of segments that can provide the
quality display for the characters. Here the gap between
neighbor characters needs not to be considered. For
example, to represent the isolated form of Lam (ل), we
used
{a,d,o,s} in lieu of {b,g,k,q,r}.
(
a
)
(
b
)
Figure 1. (a)The Model of 18 segments for Arabic
A
lphabetic Characters, (b)The Model of 25 segments
for Complete Arabic Alphanumeric Characters
In the case of initial forms, there are two major aspects
for consideration – display quality and the gap between
the target initial character and its left neighbor character.
If we want to provide a quality appearance for a
sequence of characters, we have to reduce the gap
between the target character and its left neighbor
character. So, to represent the an initial character, we
took the segments from the left side of the grid structure
as far as possible and try to extend the character by
taking maximum number of segments from left side of
the base line for reducing the gap with its left neighbor.
Such as for initial form of Ain (ع),
{e,k,q} is chosen
instead of
{i,g,k,l,q}.
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For the medial form, three major issues are addressed-
display quality and two gaps between the target
character and both left and right neighbors. So, to
represent the target character we choose minimum
number of segments and try to extend the character by
taking maximum number of segments from both left and
right side of the base line for reducing the gap with its
left and right neighbor characters. Such as in lieu of
{g,k,l,y}, {g,k,l,m,q,y} is used to represent the
medial form of Ba (ب).
For the final form, we considered two major issues –
display quality and the gap between the target character
and its right neighbor. To represent the target character
we choose the segments from the right side of the grid
structure as far as possible and try to extend the
character by taking maximum numbers of segments
from right side of the base line in order to reduce the gap
between the target character and its right neighbor. Such
as to display the final form of Alif (ا),
{b,g,l,m } is
chosen in lieu of
{a,d,k,l,m}.
4 Characterization of Arabic Alpha-
numeric Characters by Using the
Proposed Segmented Display Unit
All Arabic alphanumeric characters along with their four
forms can be represented by using different
combinations of non-overlapping 25 segments: a, b, c, d,
e, f, g, h, i, j, k ,l, m, n, o, p q, r, s, t, u, v, w, x, and y.
The structure of non-overlapping segments is already
shown in Fig.1(b). Table 1 presents partial Arabic
alphanumeric characters as a sample generated by using
this display unit. We get the truth table for Arabic
alphanumeric characters from Table 1, which is shown
in Table 2. In Table 2, each index value corresponds to
decimal equivalent of respective 7-bit input pattern,
which also precedes every character in Table 1. The
truth table yields us Boolean function for each of the 25
segments. K-map minimization software [11] is used to
minimize them. The minimized Boolean functions are
shown in Table 4. To list all Arabic alphanumeric
characters in their four forms, we use the following
notation:
Character Name, Basic Symbol {(segments used to
represent isolated form), (segments used to represent
final form), (segments used to represent medial form),
(segments used to represent initial form)}
If any particular form is absent for a character, NULL is
used instead of segment list. For example, by using the
above notation four forms of Ghain (غ) are listed as
follows:
Ghain, غ {(e,k,n,t,v),(e,g,k,l,m,n,t,v), (h,i,j,k,l,m,q,w),
(e,k,q,u)}
Here, the isolated form of Ghain (غ) is represented by e,
k, n, t, and v segments; the final form of Ghain (ﻎ) is
represented by e, g, k, l, m, n, t, and v segments; the
medial form of Ghain (ﻐ) is represented by h, i, j, k, l, m,
q, and w segments; the initial form of Ghain (ﻏ) is
represented by e, k, q, and u segments. In this way, all
Arabic alphanumeric characters are represented. Some
characters are shown in Table 3 as samples.
Some minimized Boolean functions for segments out of
25 are shown in Table 4 as sample.
6 Conclusions
The paper emphasized on a successful display of four
forms of Arabic alphanumeric characters through
proposed 25-segment display unit. The strength of this
design is that it is capable of writing consecutive
characters to form Arabic strings. The display structure
is designed without any intersection of the constituent
segments. Moreover it follows the same base line for all
characters, which is a must to write Arabic words. From
now onwards, the proposed design may be used rather
than dot matrices to represent Arabic alphanumeric
characters, which is more efficient, cost effective and
consumes less storage. In future, attempts will be made
to include the display of punctuation and special
characters of Arabic Language and Urdu alphanumeric
characters along with the present system.
Figure 2. Overall block diagram of the
complete Arabic
display driver system.
Driving
Circuit
25 segments
(a,b,..x,y)
7-bit input
(A,B,C,D,
E,F,G)
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Table 1. Representation of Arabic Alphanumeric Characters by Using Proposed 25-Segment
Display Unit
Serial
Number
Letter Name Isolated Form Final Form Medial Form Initial Form
1 Alif
0.
1.
2 Tha / Sa
10.
11. 12. 13.
3 Kha
22.
23. 24. 25.
4 Zai / Za
32.
33.
5 Sheen
38.
39. 40. 41.
6 Dad / Dwad
46. 47. 48. 49.
7 Zhoa
52.
53.
8 Ghain
58.
59. 60. 61.
9 Fa
62.
63. 64. 65.
10 Kaf
70.
71. 72. 73.
11 Ya
95.
96. 97. 98.
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Table 2. Table for Arabic Alphanumeric Characters Using 25-segments Display
Index
No
Shape a b c d e f g h i j k l m n o p q r s t u v w x y
0
1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1
0 1 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0
10
0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 1 1 0 0 1 1 1 0 0
11
0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 1 1 0 0 1 1 1 0 0
12
0 0 0 0 0 0 1 0 0 0 1 1 1 0 0 0 1 0 0 0 1 1 1 0 0
13
0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 1 1 1 0 0
22
0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 1 0 0 0 1 1 0 0 0 0
23
0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 1 0 0 0 1 1 0 0 0 0
24 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 0 1 0 0 0 0 1 0 0 0
25
0 0 0 0 0 1 0 1 0 0 1 1 0 0 0 0 1 0 0 0 0 1 0 0
0
32
0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0
33
0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 0 0 0 1 0 0 0
38
0 0 0 1 0 0 1 0 0 1 1 1 0 0 1 0 0 0 1 0 1 1 1 0 0
39
0 0 0 1 0 0 1 0 0 1 1 1 1 0 1 0 0 0 1 0 1 1 1 0 0
40
0 0 0 1 0 0 1 0 0 1 1 1 1 0 0 0 1 0 0 0 1 1 1 0 0
41
0 0 0 1 0 0 1 0 0 1 1 1 0 0 0 0 1 0 0 0 1 1 1 0 0
46
0 0 0 1 1 0 0 0 1 1 1 1 0 0 1 0 0 0 1 0 0 1 0 0 0
47
0 0 0 1 1 0 0 0 1 1 1 1 1 0 1 0 0 0 1 0 0 1 0 0 0
48
0 0 0 1 1 0 0 0 1 1 1 1 1 0 0 0 1 0 0 0 0 1 0 0 0
49
0 0 0 1 1 0 0 0 1 1 1 1 0 0 0 0 1 0 0 0 0 1 0 0 0
52
1 0 0 1 1 0 0 0 1 1 1 1 0 0 0 0 1 0 0 0 0 1 0 0 0
53
1 0 0 1 1 0 0 0 1 1 1 1 1 0 0 0 1 0 0 0 0 1 0 0 0
58
0 0 0 0 1 0 0 0 0 0 1 0 0 1 0 0 0 0 0 1 0 1 0 0 0
59
0 0 0 0 1 0 1 0 0 0 1 1 1 1 0 0 0 0 0 1 0 1 0 0 0
60
0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 1 0 0 0 0 0 1 0 0
61
0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 1 0 0 0 0
62
0 0 0 0 1 0 1 0 0 0 1 0 0 1 0 0 0 0 1 0 1 0 0 0 0
63
0 0 0 0 1 0 1 0 0 0 1 1 1 1 0 0 0 0 1 0 1 0 0 0 0
64
0 0 0 0 1 0 1 0 0 0 1 1 1 0 0 0 1 0 0 0 1 0 0 0 0
65
0 0 0 0 1 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 1 0 0 0 0
70
1 0 0 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0
71
1 0 0 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 1 0 0 0 0 0 0
72
0 0 1 0 0 0 0 0 1 1 1 1 1 0 0 0 1 0 0 0 0 0 0 0 0
73
0 0 1 0 0 0 0 0 1 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0
95
0 0 0 0 1 0 0 0 0 0 1 0 0 1 0 0 0 0 1 0 0 0 0 1 1
96
0 0 0 0 0 1 0 1 0 0 1 0 1 1 0 0 0 0 1 0 0 0 0 1 1
97
0 0 0 0 0 0 1 0 0 0 1 1 1 0 0 0 1 0 0 0 0 0 0 1 1
98
0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 1 1
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Table 4. Simplified Boolean Functions For
Segments
Name of
Segments
Simplified Boolean Functions
a
a = ∑ (A´B´C´D´G´F´E´ + A´B´CG´FE +
A´BC´G´FE + A´BCGF´E´ + ABC´GF´E +
AB´CGF´E´);
b
b = ∑ (A´B´C´DG´F´E´ + A´BCD´GF´E +
ABC´GF´);
c
c = ∑ (A´BCD´GF´E + AB´C´GF´E´);
d
d = ∑ (A´B´C´D´G´F´E´ + AB´C´DFE´ +
A´BCGF´E´ + ABC´GF´E + AB´CGF´E´ +
A´B´G´FE + A´BC´G´F + A´BC´FE´ +
A´BD´FE´ + CG´FE´ + AG´FE´);
v
v = ∑ (ABC´G´F´E´ + AB´CG´F´E´ +
AB´C´G´F´E + AB´CG´FE + A´B´CGF´E´
+ B´C´G´FE´ + A´C´G´FE + BCG´FE´ +
A´BC´GF´);
W
w = ∑ (ABC´D´G´E + A´BCG´E´ +
ABC´G´F´ + AB´G´F´E´ + AB´C´G´E´);
X
x = ∑ (ABCDGF´E + A´B´CG´F´E´ +
ABCG´F´E´ + A´B´C´GFE´ + A´B´D´
GFE´);
y
y= ∑ (ABCDGF´E + A´B´C´G´F´E +
A´BC´G´F´E´ + A´B´GFE´);
References:
[1] Cook B.M. and White N.H., Computer
Peripherals, 3
rd
Edition, United Kingdom, pp.
43-45, 2003.
[2] Hall D.V., Microprocessor and Interfacing:
Programming and Hardware, 2
nd
Edition, Tata
McGraw-Hill Publishing Co. Ltd., New Delhi,
2003, pp. 4, 267.
[3] Rahman M.O., and Kabir S.M.L., “Designing
26-Segments Display for Bangla Characters”,
Asian Journal of Information Technology,
Vol.3 No.8, pp. 583-588, 2004.
[4] Mahmud S., Arefin A.S. and Khan M.I., “A
New Approach for Displaying All Bengali
Characters”, Asian Journal of Information
Technology, vol.4 No.2, pp.194-197, 2005.
[
Table 3. Arabic alphanumeric characters in their
four forms
Serial
No.
Structural components of Four Forms of
Arabic Alphanumeric Characters
1. Alif, ا {(a,d), (b,g,l,m), (NULL),(NULL)}
2. Tha/Sa,ث{(j,k,l,q,r,u,v,w),(j,k,l,m,q,r,u,v,w),
(g,k,l,m,q,u,v,w),(g,k,q,u,v,w)}
3. Kha, خ {(k,n,p,t,u), (k,l,m,n,p,t,u),
(f,h,k,l,m,q,v), (f,h,k,l,q,v)}
4. Zai/Za, ز {(g,n,v), (g,l,m,n,v), (NULL),
(NULL)}
5. Sheen,ش{(d,g,j,k,l,o,s,u,v,w),(d,g,j,k,l,m,o,s,u,
v,w), (d,g,j,k,l,m,q,u,v,w), (d,g,j,k,l,q,u,v,w)}
6. Dad/Dwad,ض{(d,e,i,j,k,l,o,s,v),(d,e,i,j,k,l,m,o,
s,v), (d,e,i,j,k,l,m,q,v), (d,e,i,j,k,l,q,v)}
7. Zhoa, ظ {(a,d,e,i,j,k,l,q,v), (a,d,e,i,j,k,l,m,q,v),
(NULL), (NULL)}
8. Ghain, غ {(e,k,n,t,v),(e,g,k,l,m,n,t,v),
(h,i,j,k,l,m,q,w), (e,k,q,u)}
5] Chowdhury M.S., “A Segmented Display
system for Bengali Composite Letters”, The
Chittagong University Journal of Science, vol.
29(2), pp. 19-24, 2005.
9. Fa, ف {(e,g,k,n,s,u), (e,g,k,l,m,n,s,u),
(e,g,k,l,m,q,u), (e,g,k,q,u)}
10. Kaf, ك {(a,d,o,p,q,r,s), (a,d,k,l,m,o,p,q,r,s),
(c,i,j,k,l,m,q), (c,i,j,k,l,q)}
[6] Rahman M.O., Azim M.A., Chowdhury
M.S., Islam M.N., “Different Segment
displays for Bangla, English and Arabic
digits”, in Proceedings of the 6
11. Ya, ي {(e,k,n,s,x,y), (f,h,k,m,n,s,x,y),
(g,k,l,m,q,x,y), (g,k,q,x,y)}
th
ICCIT,
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Kaushik Roy, “Development of 16-
segment Multilingual Display Driver”, in
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Chowdhury M.C., “Designing Display Unit
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http://www.sakkal.com/ArtArabicCalligrap
hy.html
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[11] ‘Karnaugh Map Minimizer v0.4’, Available:
http://k-map.sourceforge.net/
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ISBN: 978-960-6766-67-1
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ISSN: 1790-2769
