 |
 |
|
| S6B0741 |
|
|||||||||||||||||
 SAMSUNG
|
| |||||||||||||||||
|
28 page 
128 SEG / 129 COM DRIVER & CONTROLLER FOR STN LCD S6B0741 24 Oscillator This is on-chip Oscillator with external resistor. Its frequency is controlled by external resistor between OSC1 and VDD. This oscillator signal is used in the voltage converter and display timing generation circuit. Display Timing Generator Circuit This circuit generates some signals to be used for displaying LCD. The display clock, CL(internal), 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 128-bit 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 a 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 9. FR(Internal) M(Internal) 127 128 1 2 3 4 5 6 7 8 9 10 11 12 121 122 123 124 125 126 127 128 1 2 3 4 5 6 CL(Internal) COM0 V0 V1 V2 V3 V4 VSS COM1 V0 V1 V2 V3 V4 VSS V0 V1 V2 V3 V4 VSS SEGn Figure 9. 2-frame AC Driving Waveform (Duty Ratio = 1/128) |
