ST7625 datasheet(39/160 Pages) SITRONIX

39 / 160 page

ST7625

Ver 1.6

39/160

2008/07

7.4 Gray-Scale Display

ST7625 incorporates a 4FRC & 31 PWM function circuit to display a 64 gray-scale display.

7.5 Oscillation circuit

ST7625 has a built-in an oscillator circuit. It provides internal clock without using external resistor. This oscillator signal is

used in the voltage converter and display timing generation circuit.

7.6 Display Timing Generator Circuit

This circuit generates some signals for displaying LCD. The display clock, which is generated by oscillation clock,

generates the clock for the line counter and the signal for the display data latch. The line address of on-chip RAM is

generated in synchronization with the display clock and the display data latch circuit latches the 96-bits display data in

synchronization with the display clock. The display data, which is read to the LCD driver, is completely independent of the

access to the display data RAM from the microprocessor. The display clock generates an LCD AC signal (M), which

enables the LCD driver to make an AC drive waveform, and also generates an internal common timing signal and start

signal to the common driver. The frame signal or the line signal changes the M by setting internal instruction. Driving

waveform and internal timing signal are shown in Figure 7.5.

Figure 7.5 2-frame AC Driving Waveform (Duty Ratio: 1/96)

ST7625 Datasheet(PDF) 39 Page - Sitronix Technology Co., Ltd.