PIC16F946T-I/PT Microchip Technology, PIC16F946T-I/PT Datasheet - Page 115

• Manufacturer Part Number: PIC16F946T-I/PT
• Description: Microcontroller
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F946T-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 336 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MA160011 - DAUGHTER BOARD PICDEM LCD 16F91X
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

9.7
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.
FIGURE 9-6:
© 2005 Microchip Technology Inc.
COM0
LCD Waveform Generation
TYPE-A/TYPE-B WAVEFORMS IN STATIC DRIVE
COM0-SEG0
COM0-SEG1
COM0
SEG0
SEG1
Preliminary
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 on each frame
boundary. Thus, Type-A waveform maintains ‘0’ V
over a single frame, whereas Type-B waveform takes
two frames.
Figure 9-6 through Figure 9-16 provide waveforms for
static,
quarter-multiplex drives for Type-A and Type-B
waveforms.
Note 1: If Sleep has to be executed with LCD
1 Frame
2: When the LCD clock source is F
half-multiplex,
Sleep enabled (LCDCON<SLPEN> is
‘1’), then care must be taken to execute
Sleep only when V
‘0’.
if Sleep is executed, irrespective of the
LCDCON<SLPEN> setting, the LCD goes
into Sleep. Thus, take care to see that V
on all pixels is ‘0’ when Sleep is executed.
PIC16F946
one-third-multiplex
DC
on all the pixels is
DS41265A-page 113
OSC
/8192,
V
V
V
V
V
V
V
V
-V
V
1
0
1
0
1
0
1
0
0
1
and
DC
DC