LC7982A Datasheet, PDF (10/18 Pages) Sanyo Semicon Device – LCD Dot Matrix Graphics Display Controller

LC7982A
• Character count setting
Register
R/W RS DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
Instruction register
01 00000010
Character count register
00
(H_N – 1) binary
In character display mode, H_N specifies the number of characters displayed in the horizontal direction. In graphics
mode, H_N specifies the number of bytes displayed in the horizontal direction. The total number of dots displayed on
the screen in the horizontal direction is given by the following formula.
n = HP × H_N
H_N can be set to an even number in the range 2 to 256 (decimal).
• Time division setting (display duty)
Register
Instruction register
Duty register
R/W RS
01
00
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
00000011
(N_X – 1) binary
N_X specifies the time division setting. That is, the display duty is set to 1/N_X.
N_X can be set to a value in the range 1 to 256 (decimal).
• Cursor position setting
Register
Instruction register
Cursor position register
R/W RS
01
00
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
00000100
0000
(CP – 1) binary
In character display mode, CP specifies the line where the cursor is displayed. For example, if CP is set to 8 (decimal),
the cursor will be displayed under the character for a 5 × 7 font. The length of the cursor in the horizontal direction will
be equal to horizontal direction character pitch HP. While CP can be set to any value in the range 1 to 16 (decimal), if
it is set to a value less than or equal to the vertical direction character pitch VP (CP ≤ VP), the cursor display will take
priority when cursor display is enabled. Note that if CP > VP, the cursor will not be displayed. The length of the cursor
in the horizontal direction will be equal to HP.
• Display start position low-order address
Register
R/W RS
Instruction register
01
Display start address register
(Low-order byte)
00
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
00001000
(Start address low-order byte) binary
• Display start position high-order address
Register
R/W RS
Instruction register
01
Display start address register
(High-order byte)
00
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
00001001
(Start address high-order byte) binary
These instructions together write the display start address value into the display start address register. The display start
address specifies the RAM address where the data to be displayed at the upper left of the screen is stored.
The start address is a 16-bit value formed from high-order and low-order bytes.
• Cursor address (low order) setting (RAM read/write low-order address)
Register
Instruction register
Cursor address counter
(Low-order byte)
R/W RS DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
01 00001010
00
(Cursor address low-order byte) binary
No. 5946-10/18