PIC16F913 datasheet(112/272 Pages) MICROCHIP

112 / 272 page

PIC16F917/916/914/913

DS41250E-page 110

Preliminary

9.7

LCD Waveform Generation

LCD waveforms are generated so that the net AC

voltage across the dark pixel should be maximized and

the net AC voltage across the clear pixel should be

minimized. The net DC voltage across any pixel should

be zero.

The COM signal represents the time slice for each

common, while the SEG contains the pixel data.

The pixel signal (COM-SEG) will have no DC compo-

nent and it can take only one of the two rms values. The

higher rms value will create a dark pixel and a lower

rms value will create a clear pixel.

As the number of commons increases, the delta

between the two rms values decreases. The delta

represents the maximum contrast that the display can

have.

The LCDs can be driven by two types of waveform:

Type-A and Type-B. In Type-A waveform, the phase

changes within each common type, whereas in Type-B

waveform,

the

phase

changes

each

frame

boundary. Thus, Type-A waveform maintains 0 VDC

over a single frame, whereas Type-B waveform takes

two frames.

Figure 9-5 through Figure 9-15 provide waveforms for

static,

half-multiplex,

one-third-multiplex

and

quarter-multiplex

drives

for

Type-A

and

Type-B

waveforms.

FIGURE 9-5:

TYPE-A/TYPE-B WAVEFORMS IN STATIC DRIVE

Note 1: If Sleep has to be executed with LCD

Sleep enabled (LCDCON<SLPEN> is

‘1’), then care must be taken to execute

Sleep only when VDC on all the pixels is

‘0’.

2: When the LCD clock source is FOSC/8192,

if Sleep is executed, irrespective of the

LCDCON<SLPEN> setting, the LCD goes

into Sleep. Thus, take care to see that VDC

on all pixels is ‘0’ when Sleep is executed.

COM0

SEG0

COM0-SEG0

COM0-SEG1

SEG1

-V1

1 Frame

COM0

PIC16F913 Datasheet(PDF) 112 Page - Microchip Technology

PIC16F913 Datasheet(HTML) 112 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL