PIC16F877A-I/L Microchip Technology, PIC16F877A-I/L Datasheet - Page 143

• Manufacturer Part Number: PIC16F877A-I/L
• Description: IC MCU FLASH 8KX14 EE 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877A-I/L

• Program Memory Type: FLASH
• Program Memory Size: 14KB (8K x 14)
• Package / Case: 44-PLCC
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• 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: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: I2C/SPI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Package: 44PLCC
• Device Core: PIC
• Family Name: PIC16
• Maximum Speed: 20 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164309 - MODULE SKT FOR PM3 44PLCC444-1001 - DEMO BOARD FOR PICMICRO MCUDVA16XL441 - ADAPTER DEVICE ICE 44PLCC309-1040 - ADAPTER 44-PLCC ZIF TO 40-DIP309-1039 - ADAPTER 44-PLCC TO 40-DIPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: PIC16F877AI/L

13.0
The Comparator Voltage Reference Generator is a
16-tap resistor ladder network that provides a fixed
voltage reference when the comparators are in mode
‘
the reference generator. Register 13-1 lists the bit
functions of the CVRCON register.
As shown in Figure 13-1, the resistor ladder is seg-
mented to provide two ranges of CV
a power-down function to conserve power when the
reference is not being used. The comparator reference
REGISTER 13-1:
 2003 Microchip Technology Inc.
110’
. A programmable register controls the function of
COMPARATOR VOLTAGE
REFERENCE MODULE
bit 7
bit 6
bit 5
bit 4
bit 3-0
CVRCON CONTROL REGISTER (ADDRESS 9Dh)
bit 7
CVREN: Comparator Voltage Reference Enable bit
1 = CV
0 = CV
CVROE: Comparator V
1 = CV
0 = CV
CVRR: Comparator V
1 = 0 to 0.75 CV
0 = 0.25 CV
Unimplemented: Read as ‘0’
CVR3:CVR0: Comparator V
When CVRR = 1:
CV
When CVRR = 0:
CV
Legend:
R = Readable bit
-n = Value at POR
CVREN
R/W-0
REF
REF
= (VR<3:0>/ 24) (CV
= 1/4 (CV
REF
REF
REF
REF
REF
circuit powered on
circuit powered down
voltage level is output on RA2/AN2/V
voltage level is disconnected from RA2/AN2/V
RSRC
CVROE
R/W-0
values and has
RSRC
to 0.75 CV
RSRC
REF
, with CV
REF
) + (VR3:VR0/ 32) (CV
R/W-0
CVRR
Range Selection bit
Output Enable bit
REF
W = Writable bit
‘1’ = Bit is set
RSRC
RSRC
RSRC
Value Selection bits 0
, with CV
)
/24 step size
U-0
—
supply voltage (also referred to as CV
directly from V
voltage at the top of the ladder is CV
where V
switch transistor. This reference will only be as
accurate as the values of CV
The output of the reference generator may be con-
nected to the RA2/AN2/V
used as a simple D/A function by the user if a very high-
impedance load is used. The primary purpose of this
function is to provide a test path for testing the
reference generator function.
RSRC
RSRC
/32 step size
REF
SAT
R/W-0
CVR3
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
-/CV
)
is the saturation voltage of the power
DD
VR3:VR0
REF
. It should be noted, however, that the
REF
pin
R/W-0
-/CV
PIC16F87XA
CVR2
REF
REF
15
RSRC
-/CV
pin
x = Bit is unknown
R/W-0
REF
CVR1
and V
DS39582B-page 141
pin. This can be
RSRC
SAT
RSRC
.
R/W-0
CVR0
) comes
– V
bit 0
SAT
,