PIC16F877-20/P Microchip Technology, PIC16F877-20/P Datasheet - Page 362

• Manufacturer Part Number: PIC16F877-20/P
• Description: IC MCU FLASH 8KX14 EE 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877-20/P

• Core Size: 8-Bit
• Program Memory Size: 14KB (8K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PICmicro MID-RANGE MCU FAMILY
19.1
DS31019A-page 19-2
VREN
Note 1: See
Introduction
parameter D312
V
REF
The Voltage Reference module is typically used in conjunction with the Comparator module. The
comparator module’s inputs do not require very large drive, and therefore the drive capability of
the Voltage Reference is limited.
The Voltage Reference is a 16-tap resistor ladder network that provides a selectable voltage ref-
erence. The resistor ladder is segmented to provide two ranges of V
power-down function to conserve power when the reference is not being used. The VRCON reg-
ister controls the operation of the reference as shown in
in
result in an increasing output).
Figure 19-1:
Table 19-1: Typical Voltage Reference with V
Figure
VR3:VR0
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
8R
(1)
19-1. Within each range, the 16 steps are monotonic (i.e. each increasing code will
in the Electrical Specifications section of the device data sheet.
Voltage Reference Block Diagram
R
(1)
VRR = 1
0.00 V
0.21 V
0.42 V
0.63 V
0.83 V
1.04 V
1.25 V
1.46 V
1.67 V
1.88 V
2.08 V
2.29 V
2.50 V
2.71 V
2.92 V
3.13 V
R
(1)
V
REF
16 Stages
16-1 Analog MUX
VRR = 0
1.25 V
1.41 V
1.56 V
1.72 V
1.88 V
2.03 V
2.19 V
2.34 V
2.50 V
2.66 V
2.81 V
2.97 V
3.13 V
3.28 V
3.44 V
3.59 V
R
(1)
DD
= 5.0V
R
(1)
Figure
19-1. The block diagram is given
8R
1997 Microchip Technology Inc.
(1)
VR3
VR0
REF
(From VRCON<3:0>)
values and has a
VRR