PIC18F2480-I/SO Microchip Technology, PIC18F2480-I/SO Datasheet - Page 265

• Manufacturer Part Number: PIC18F2480-I/SO
• Description: IC PIC MCU FLASH 8KX16 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2480-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 16KB (8K x 16)
• Package / Case: 28-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 25
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: SPI/I2C/USART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 25
• Number Of Timers: 4
• Operating Supply Voltage: 5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163011, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28SO-1 - SOCKET TRANSITION 28SOIC 300MIL
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

21.0
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable reference
voltage. Although its primary purpose is to provide a
reference for the analog comparators, it may also be
used independently of them.
A block diagram is of the module shown in
Figure 21-1.The resistor ladder is segmented to
provide two ranges of CV
power-down function to conserve power when the
reference is not being used. The module’s supply
reference can be provided from either device V
or an external voltage reference.
21.1
The voltage reference module is controlled through the
CVRCON register (Register 21-1). The comparator
voltage reference provides two ranges of output
REGISTER 21-1:
© 2007 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3-0
Note 1:
CVREN
R/W-0
COMPARATOR VOLTAGE
REFERENCE MODULE
Configuring the Comparator
Voltage Reference
CVROE overrides the TRISA<0> bit setting. If enabled for output, RA2 must also be configured as an
input by setting TRISA<2> to ‘1’.
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
CVRSS: Comparator V
1 = Comparator reference source, CV
0 = Comparator reference source, CV
CVR3:CVR0: Comparator V
When CVRR = 1:
CV
When CVRR = 0:
CV
CVROE
REF
REF
R/W-0
CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
= ((CVR3:CVR0)/24) • (CV
= (CV
REF
REF
REF
REF
(1)
circuit powered on
circuit powered down
voltage level is also output on the RA0/AN0/CV
voltage is disconnected from the RA0/AN0/CV
RSRC
RSRC
REF
RSRC
W = Writable bit
‘1’ = Bit is set
values and has a
to 0.75 CV
to 0.75 CV
R/W-0
CVRR
/4) + ((CVR3:CVR0)/32) • (CV
REF
REF
REF
Range Selection bit
Source Selection bit
Output Enable bit
REF
RSRC
RSRC
PIC18F2480/2580/4480/4580
DD
CVRSS
R/W-0
Value Selection bits (0 ≤ (CVR3:CVR0) ≤ 15)
/V
, with CV
, with CV
RSRC
Preliminary
SS
RSRC
RSRC
)
RSRC
RSRC
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
= (V
= V
(1)
R/W-0
CVR3
voltage, each with 16 distinct levels. The range to be
used is selected by the CVRR bit (CVRCON<5>). The
primary difference between the ranges is the size of the
steps
(CVR3:CVR0), with one range offering finer resolution.
The equations used to calculate the output of the
comparator voltage reference are as follows:
The comparator reference supply voltage can come
from either V
V
voltage source is selected by the CVRSS bit
(CVRCON<4>).
The settling time of the comparator voltage reference
must be considered when changing the CV
(see
Characteristics”).
/24 step size
/32 step size
DD
REF
REF
RSRC
– V
If CVRR = 1:
CV
If CVRR = 0:
CV
CV
- that are multiplexed with RA2 and RA3. The
+) – (V
)
SS
REF
REF
RSRC
Table 27-3
selected
REF
= ((CVR3:CVR0)/24) x CV
REF
= (CV
REF
)
DD
R/W-0
CVR2
pin
-)
pin
and V
DD
by
x 1/4) + (((CVR3:CVR0)/32) x
in
SS
the
, or the external V
x = Bit is unknown
Section 27.0
R/W-0
CVR1
CV
REF
DS39637C-page 263
RSRC
Selection
“Electrical
REF
R/W-0
CVR0
REF
output
+ and
bit 0
bits