HD66730 Datasheet, PDF (88/131 Pages) Hitachi Semiconductor – Dot-Matrix Liquid Crystal Display Controller/Driver Supporting Japanese Kanji, Korean Font Display

HD66730/HD66731
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 × 12 dots) and 6-dot half-size characters (character size: 6 × 12 dots). There will be a one-dot space
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 × 13
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 Relationship between JIS Codes and HD66730 Character Codes
• 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)
JIS
Non-kanji
Level 1 kanji
Level 1 kanji
User font
Character Code Arrangement of HD66730
b7 b6 b5 C11 C10 C9 C8 C7 C6 C5 C4 C3 C2 C1 C0
0 1 0 a7 a6 b3 b2 b1 0 0 a5 a4 a3 a2 a1
0 1 1 b7 b4 b3 b2 b1 a7 a6 a5 a4 a3 a2 a1
1 0 0 b7 b4 b3 b2 b1 a7 a6 a5 a4 a3 a2 a1
— — — 0 0 0 0 0 0 0 0 0 u2 u1 u0
Upper byte
Lower byte
87