HD44780 Hitachi Semiconductor (acquired by Renesas), HD44780 Datasheet - Page 32

• Manufacturer Part Number: HD44780
• Description: Dot Matrix Liquid Crystal Display Controller/driver
• Manufacturer: Hitachi Semiconductor (acquired by Renesas)

HD44780U
Interfacing the HD44780U
Interface to MPUs
32
Interfacing to an 8-bit MPU
See Figure 16 for an example of using a I/O port (for a single-chip microcomputer) as an interface
device.
In this example, P30 to P37 are connected to the data bus DB0 to DB7, and P75 to P77 are connected to
E, R/W, and RS, respectively.
RS
R/W
E
Internal
operation
DB7
H8/325
P30 to P37
Instruction
write
Figure 15 Example of Busy Flag Check Timing Sequence
Data
P77
P76
P75
Figure 16 H8/325 Interface (Single-Chip Mode)
Busy flag
check
Busy
Functioning
8
Busy flag
check
Busy
DB0 to DB7
E
RS
R/W
HD44780U
COM1 to
SEG1 to
Busy flag
check
COM16
SEG40
Not
busy
16
40
Instruction
write
Data
LCD