PIC16F87-I/P Microchip Technology, PIC16F87-I/P Datasheet - Page 129

• Manufacturer Part Number: PIC16F87-I/P
• Description: IC MCU FLASH 4KX14 EEPROM 18DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F87-I/P

• Program Memory Type: FLASH
• Program Memory Size: 7KB (4K x 14)
• Package / Case: 18-DIP (0.300", 7.62mm)
• 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: 16
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: SSP/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163014
• Minimum Operating Temperature: - 40 C
• Package: 18PDIP
• Device Core: PIC
• Family Name: PIC16
• Maximum Speed: 20 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: ACICE0202 - ADAPTER MPLABICE 18P 300 MILAC164010 - MODULE SKT PROMATEII DIP/SOIC
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

14.0
The comparator voltage reference generator is a 16-tap
resistor ladder network that provides a fixed voltage
reference when the comparators are in mode ‘010’. A
programmable register controls the function of the refer-
ence generator. Register 14-1 lists the bit functions of
the CVRCON register.
As shown in Figure 14-1, 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 14-1:
 2005 Microchip Technology Inc.
COMPARATOR VOLTAGE
REFERENCE MODULE
bit 7
bit 6
bit 5
bit 4
bit 3-0
CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
(ADDRESS 9Dh)
Legend:
R = Readable bit
-n = Value at POR
bit 7
CVREN: Comparator Voltage Reference Enable bit
1 = CV
0 = CV
CVROE: Comparator V
1 = CV
0 = CV
CVRR: Comparator V
1 = 0.00 CV
0 = 0.25 CV
Unimplemented: Read as ‘0’
CVR<3:0>: Comparator V
When CVRR = 1:
CV
When CVRR = 0:
CV
CVREN
R/W-0
Note 1: V
REF
REF
REF
REF
REF
REF
= (VR<3:0>/24) (CV
= 1/4 (CV
circuit powered on
circuit powered down
voltage level is output on the RA2/AN2/CV
voltage level is disconnected from the RA2/AN2/CV
RSRC
RSRC
REF
REF
CVROE
R/W-0
values and has
is available on the PIC16F88 device only.
to 0.625 CV
to 0.72 CV
RSRC
REF
REF
) + (VR3:VR0/32) (CV
Range Selection bit
REF
R/W-0
CVRR
Output Enable bit
RSRC
W = Writable bit
‘1’ = Bit is set
RSRC
RSRC
Value Selection 0
with CV
)
with CV
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
connected to the RA2/AN2/CV
available on the PIC16F88 device only). This can be
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.
U-0
RSRC
—
RSRC
(1)
/32 step size
RSRC
/24 step size
SAT
VR3:VR0
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-0
CVR3
)
REF
is the saturation voltage of the power
DD
/V
. It should be noted, however, that the
REF
15 bits
PIC16F87/88
REF
- pin
R/W-0
CVR2
/V
(1)
REF
(1)
RSRC
REF
- pin
x = Bit is unknown
R/W-0
CVR1
/V
and V
DS30487C-page 127
(1)
REF
RSRC
- pin (V
SAT
RSRC
.
R/W-0
CVR0
) comes
– V
REF
bit 0
SAT
- is
,