MSM6222 OKI [OKI electronic componets], MSM6222 Datasheet - Page 25

• Manufacturer Part Number: MSM6222
• Description: DOT MATRIX LCD CONTROLLER WITH 16-DOT COMMON DRIVER AND 40-DOT SEGMENT DRIVER
• Manufacturer: OKI [OKI electronic componets]

¡ Semiconductor
Data Bus Connected with CPU
The data bus connected with CPU is available either once for 8 bits or twice for 4 bits. This
allows the MSM6222B-xx to be interfaced with either an 8-bit or 4-bit CPU.
(1) When the interface data length is 8 bits
(2) When the interface data length is 4 bits
Data buses DB
one step.
The 8-bit data input/output is carried out in two steps by using only high-order 4 bits
of data buses DB
The first time data input/output is made for 4-high order bits (DB
interfaces data length is 8 bits) and the second time data input/output is made for low-
order 4 bits (DB
input/output can be completely made through high-order 4 bits, be sure to make
another input/output of low-order 4 bits. (Example: Busy flag Read).
Since the data input/output is carried out in two steps but as one execution, no normal
data transfer is executed from the next input/output if accessed only once.
0
0
to DB
4
to DB
to DB
7
3
(8 buses) are all used and data input/output is carried out in
7
when the interface data length is 8 bits). Even when the data
(4 buses)
4
to DB
MSM6222B-xx
7
when the
25/45