PIC16F84A-20/SS Microchip Technology, PIC16F84A-20/SS Datasheet - Page 477

• Manufacturer Part Number: PIC16F84A-20/SS
• Description: IC MCU FLASH 1KX14 EE 20SSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F84A-20/SS

• Core Size: 8-Bit
• Program Memory Size: 1.75KB (1K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Peripherals: POR, WDT
• Number Of I /o: 13
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 68 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 20-SSOP
• Controller Family/series: PIC16F
• No. Of I/o's: 13
• Eeprom Memory Size: 64Byte
• Ram Memory Size: 68Byte
• Cpu Speed: 20MHz
• No. Of Timers: 1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT20SS1-1 - SOCKET TRANSITION 20DIP 20SSOPI3-DB16F84A - BOARD DAUGHTER ICEPIC3AC164307 - MODULE SKT FOR PM3 28SSOPAC164018 - MODULE SKT PROMATEII 20SSOP
• Data Converters: -
• Connectivity: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

1997 Microchip Technology Inc.
Note:
COM0 - SEGx [ON] =
COM0 - SEGx [OFF] =
V
V
D = V
Refer to Figure 25-6
RMS
RMS
V
[ON] =
[OFF] =
RMS
RMS
[ON]
[OFF]
The next example is for Figure 25-6 which is a 1/4 MUX, 1/3 BIAS waveform. For this example,
the values 3, 2, 1 and 0 will be assigned to V
DC voltage, RMS voltage and discrimination ratio calculations are shown in
Example 25-4:
As shown in these examples, static displays have excellent contrast. The higher the multiplex
ratio of the LCD, the lower the discrimination ratio, and therefore, the lower the contrast of the
display.
Table 25-5
and BIAS.
As the multiplex of the LCD panel increases, the discrimination ratio decreases. The contrast of
the panel will also decrease, so to provide better contrast the LCD voltages must be increased
to provide greater separation between each level.
Table 25-5: Discrimination Ratio vs. MUX and Bias
1/2 MUX
1/3 MUX
1/4 MUX
STATIC
V
V
= 3
shows the V
1
3 - 3 + 1 - 1 + 1 - 1 + 1 - 1
1 - 1 - 1 + 1 - 1 + 1 - 1 + 1
(1)
(3)
2
2
V
V
Discrimination Ratio Calculation 1/4 MUX
+ (-1)
+ (-3)
0.333
0.333
0.333
V
= 1.732
OFF
0
OFF
2
2
+ (-1)
+ (1)
, V
ON
2
1/3 BIAS
2
+ (-1)
and discrimination ratios of the various combinations of MUX
0.745
0.638
0.577
+ (1)
V
1
ON
2
2
8
8
+ (-1)
+ (1)
3
2
2.236
1.915
1.732
, V
2
+ (-1)
D
+ (1)
2
, V
V
V
DC
DC
1
Section 25. LCD
2
2
, and V
+ (-1)
= 0
= 0
+ (1)
2
2
0
+ (-1)
+ (1)
respectively. The frame equation,
2
2
=
DS31025A-page 25-19
=
Example
3
V
V
25-4.
25