hd66731a01tb0l Renesas Electronics Corporation., hd66731a01tb0l Datasheet - Page 88

• Manufacturer Part Number: hd66731a01tb0l
• Description: Dot-matrix Liquid Crystal Display Controller/driver Supporting Japanese Kanji, Korean Font Display - Hitachi Semiconductor
• Manufacturer: Renesas Electronics Corporation.

Combined Display of Full-Size and Half-Size Characters
The HD66730/1 performs display from the left edge of the display combining 12-dot full-size (character
size: 11
between these fonts.
The most significant bit in the data (8 bits) in DDRAM is allocated to the designation bit indicating a full-
size or half-size character. When this MSB is 0, the full-size character is selected, and when 1, the half-size
character is selected.
When the full-size character is selected, 2 bytes of DDRAM are linked and used as a 16-bit code (Figure
22). In this case, the lower byte is written into the smaller DDRAM address. 12 bits of this 16-bit code are
used as character codes. Up to 4096 character codes can be specified. In addition, two of the remaining four
bits can be allocated to a display-attribute code and can designate white/black inverted display for
individual characters (refer to Display Attribute Designation). Table 18 shows the relationship between the
16-bit designated JIS code and the HD66730/1 12-bit character code. 8-bit data designating half-size
characters are used as an 8-bit code (Figure 23). Specifically, 7 bits of the 8-bit half-size characters become
the character codes, so that a total of 128 characters can be displayed (alphanumeric characters and symbols
can be displayed as half-size characters).
User fonts can be displayed using the CGRAM. Special symbols not included in the internal CGROM or
the JIS Level-2 Kanji Set can be displayed as needed. Since the display font size of the CGRAM is 12
dots, CGRAM fonts can be displayed to the right, left, top or bottom, in order to be used to display double-
size characters or graphics. Note that the display-attribute code (A1/A0) designation that is to be written
into the DDRAM is ignored when the CGRAM is used. In this case, bits 6 and 7 in the CGRAM are used
for display-attribute-code designation. Refer to CGRAM for details.
Table 19
JIS
Non-kanji
Level 1 kanji
Level 1 kanji
User font
JIS first byte code: b1 to b7 (7 bits)
JIS second byte code: a1 to a7 (7 bits)
CGRAM address for user fonts: u0 to u2 (3 bits)
12 dots) and 6-dot half-size characters (character size: 6 12 dots). There will be a one-dot space
Relationship between JIS Codes and HD66730 Character Codes
b7
0
0
1
—
b6
1
1
0
—
b5
0
1
0
—
C11 C10 C9
a7
b7
b7
0
Upper byte
a6
b4
b4
0
Character Code Arrangement of HD66730
b3
b3
b3
0
C8
b2
b2
b2
0
C7
b1
b1
b1
0
C6
0
a7
a7
0
C5
0
a6
a6
0
Lower byte
C4
a5
a5
a5
0
HD66730/HD66731
C3
a4
a4
a4
0
C2
a3
a3
a3
u2
C1
a2
a2
a2
u1
C0
a1
a1
a1
u0
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