ST7522

Ver 1.0c

17/45

2002/07/10

The Reset Circuit

When the RES

―

input comes to the “L” level, these LSIs return to the default state. Their default states are as follows:

1.

Display OFF

2.

Static drive is turned OFF.

3.

ADC select: Normal (ADC command D0 = 0)

4.

Display all point on is select to normal

5.

Display normal/reverse is select to normal

6.

Power control register: (D2, D0) = (0, 0)

7.

Serial interface internal register data clear

8.

1/6 bias is selected

9.

1/17 duty is selected.

10.

Read modify write OFF

11.

Column address set to Address 0

12.

Page address set to Page 0

13.

Start line set to first line

14.

Electronic contrast register = 35H(max:3FH)

15.

OSC frequency set = 08H

16.

Follower input voltage set =02H

17.

Follower amplified ratio = 06H

18.

Booster input voltage set = 00H

When the power is turned on, the IC internal state becomes unstable, and it is necessary to initialize it using the RES

―

terminal.

After the initialization, each input terminal should

be controlled normally.

While RES

―

is “L,” the oscillator works but the display timing generator stops, and the CL, FR, terminals are fixed to “H.” The

terminals D0 to D7 are not affected.