HD66724 Datasheet, PDF (36/117 Pages) Hitachi Semiconductor – (Graphics LCD Controller/Driver with Key Scan Function)

HD66724/HD66725
Instruction Descriptions
Key Scan Data Read
In the serial interface mode, the key scan data read instruction reads scan data in scan registers SCAN0 to
SCAN3. Following transfer of the start byte, scan data read operation starts from scan register SCAN0 and
proceeds in the order of SCAN1, SCAN2, and SCAN3. When data read from SCAN 0 to SCAN3 is
completed, the operation starts from SCAN0 again. For details, see the Key Scan Control section.
R/W RS DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0
0
0
1
01
1
SE2 SE1
SSE
(SSE = 0)
SE4 SE3 _{(SSE = 1)}
0 0 0 1 1 0 0 SQ2 SQ1 SQ0
Figure 3 Key Scan Data Read Instruction
Clear Display
The clear display instruction writes space code 20H (the character pattern for character code 20H must be a
blank pattern) into all DDRAM addresses. It then sets DDRAM address 0 into the address counter. It also
sets I/D to 1 (increment mode) in the entry mode set instruction. Since the execution of this instruction
needs 85 clock cycles, do not send the next instruction during the execution time.
R/W RS DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0 00 00 0 00 01
Figure 4 Clear Display Instruction
Return Home
The return home instruction sets DDRAM address 0 into the address counter. The DDRAM contents do not
change. The cursor or blinking goes to the top left of the display.
R/W RS DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0 00 00 0 00 10
Figure 5 Return Home Instruction
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