MSM9000B-xx OKI electronic componets, MSM9000B-xx Datasheet - Page 25

• Manufacturer Part Number: MSM9000B-xx
• Description: DOT MATRIX LCD CONTROLLER
• Manufacturer: OKI electronic componets

¡ Semiconductor
Calculation Method of Various Kinds of Frequencies
• Frame frequency
• Calculating the blinking frequency
• Source oscillation frequency and busy time
For 1/16 duty
(Source clock cycle) ¥ (1/Dividing ratio) ¥ 448 = Frame cycle · · · · · (1)
For 1/9 duty
(Source clock cycle) ¥ (1/Dividing ratio) ¥ 468 = Frame cycle · · · · · (2)
Example
Source oscillation frequency = 32.768 kHz
Dividing ratio = 1/1
Specification: 1/16 Duty
Clock cycle Ts = 30.5 s
Under these conditions, the frame frequency can be calculated from expression (1) as follows:
Frame cycle Tf = 30.5 ¥ 10
Therefore
Frame frequency = 73.2 Hz
The blinking frequency can be calculated from the following expression:
Blinking frequency = (Source clock cycle) ¥ (1/Dividing ratio) ¥ 2
Example
Source oscillation frequency = 32.768 kHz
Dividing ratio = 1/1
Clock cycle T
Under these conditions, the blinking frequency can be calculated from expression (3) as
follows:
Blinking cycle Tf = 30.5 ¥ 10
Therefore
Blinking frequency = 1 Hz
When data is written to or read from RAM or a command is input, data processing time (busy
time) is taken. The maximum busy time is the source clock cycle multiplied by 10. The busy
signal (not-busy = "L", busy = "H" ) is detected at the SO pin when the serial interface is used
or at the DB0 pin when the parallel interface is used. When display data or commands are
input consecutively, a wait must be inserted for the source clock cycle multiplied by 10.
Another way is to detect busy signals and input data or commands during not-busy time only.
S
= 30.5 s
–6
–6
¥ 1 ¥ 448 = 13.66 ms
¥ 1 ¥ 2
15
= 1 s
15
· · · · · (3)
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