hd66740 Renesas Electronics Corporation., hd66740 Datasheet - Page 41

• Manufacturer Part Number: hd66740
• Description: 112 X 80-dot Graphics Lcd Controller/driver - Hitachi Semiconductor
• Manufacturer: Renesas Electronics Corporation.

Parallel Data Transfer
8-bit Bus Interface
Setting the IM2/1/0 (interface mode) to the GND/Vcc/GND level allows E-clock-synchronized 8-bit
parallel data transfer. Setting the IM2/1/0 (interface mode) to the Vcc/Vcc/GND level allows 80-
system 8-bit parallel data transfer. When the number of buses or the mounting area is limited, use a 4-
bit bus interface or serial data transfer.
4-bit Bus Interface
Setting the IM2/1/0 (interface mode) to the GND/Vcc/Vcc level allows E-clock-synchronized 4-bit
parallel data transfer using pins DB7-DB4.
level allows 80-system 4-bit parallel data transfer. The 8-bit instructions and RAM data are divided into
four upper/lower bits and the transfer starts from the upper four bits.
Note: Transfer synchronization function for a 4-bit bus interface
DB7–
DB4
R/W
RS
E
The HD66740 supports the transfer synchronization function which resets the upper/lower
counter to count upper/lower 4-bit data transfer in the 4-bit bus interface. Noise causing
transfer mismatch between the four upper and lower bits can be corrected by a reset triggered by
consecutively writing a 0000 instruction four times.
four bits.
display system.
Upper/
lower
Executing synchronization function periodically can recover any runaway in the
H8/325
Figure 17
Figure 18
"0000"
A0–A7
(1)
C0
C1
C2
*Interface via I/O port
Interface to 8-bit Microcomputer
4-bit Transfer Synchronization
"0000"
Setting the IM2/1/0 (interface mode) to the Vcc/Vcc/Vcc
(2)
8
41
"0000"
(3)
The next transfer starts from the upper
E/WR*
RS
R/W / RD*
(CS*)
DB0–DB7
(4-bit transfer synchronization)
"0000"
(4)
HD66740
Upper
HD66740
Lower