HD66730 Datasheet, PDF (83/131 Pages) Hitachi Semiconductor – Dot-Matrix Liquid Crystal Display Controller/Driver Supporting Japanese Kanji, Korean Font Display

 HD66730/HD66731
Interfacing to the MPU
The HD66730/1 enters 8-bit bus interface mode when the IM pin is set high. The HD66730/1 can interface
with the MPU via an I/O port. Use the serial interface when there are restraints in the bus wiring width.
Instruction is executed when data is written into the control register. In this case, only the status register can
be read (busy check, etc.). In this case, check the busy flag when accessing (polling), or insert an interval
considering the execution time and perform the next access when the internal process has completely
finished. The instruction execution time depends on the HD66730/1 operation frequency. When using the
internal oscillation circuit of the HD66730/1, the instruction time will change as the oscillation frequency
does. Figure 18 shows an example of an 8-bit data transfer timing sequence. Figure 19 shows an example
of interface between HD66730/1 and 8-bit microcomputers.
RS
R/W
E
Internal
signal
DB7
DB6 to
DB0
Internal operation (busy)
Data
Busy
Busy
Not
Busy
Data
Control register write Busy flag check Busy flag check Busy flag check Index register write
Figure 18 Example of an 8-bit Data Transfer Timing Sequence
C0
C1
H8/325
C2
8
A0 to A7
E
RS
R/W ^HD66730
HD66731
DB0 to DB7
I/O port interface
Figure 19 Example of Interfacing with 8-Bit Microcomputers
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