PIC18F6621-I/PT Microchip Technology, PIC18F6621-I/PT Datasheet - Page 251

• Manufacturer Part Number: PIC18F6621-I/PT
• Description: IC PIC MCU FLASH 32KX16 64TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F6621-I/PT

• Core Size: 8-Bit
• Program Memory Size: 64KB (32K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 3.75K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• Controller Family/series: PIC18
• No. Of I/o's: 53
• Eeprom Memory Size: 1024Byte
• Ram Memory Size: 3.75KB
• Cpu Speed: 40MHz
• No. Of Timers: 5
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3840 B
• Interface Type: MSSP, SPI, I2C, EUSART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 53
• Number Of Timers: 5
• 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, DV164136, DM183032
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT64PT5 - SOCKET TRAN ICE 64MQFP/TQFPAC164319 - MODULE SKT MPLAB PM3 64TQFPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Lead Free Status / Rohs Status: Details

22.0
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable voltage
reference. The resistor ladder is segmented to provide
two ranges of CV
function to conserve power when the reference is not
being used.
operation of the reference as shown in Register 22-1.
The block diagram is given in Figure 22-1.
The comparator reference supply voltage can come
from either V
V
comparator reference supply voltage is controlled by
the CVRSS bit.
REGISTER 22-1:
 2005 Microchip Technology Inc.
REF
- that are multiplexed with RA3 and RA2. The
COMPARATOR VOLTAGE
REFERENCE MODULE
bit 7
bit 6
bit 5
bit 4
bit 3-0
DD
The CVRCON register controls the
and V
REF
CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
values and has a power-down
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
bit 7
SS
Legend:
R = Readable bit
-n = Value at POR
CVREN
R/W-0
Note 1: If enabled for output, RF5 must also be configured as an input by setting TRISF<5>
, or the external V
REF
REF
= (CVR<3:0>/ 24) • (CV
= 1/4 • (CV
REF
REF
REF
REF
to ‘1’.
circuit powered on
circuit powered down
voltage level is also output on the RF5/AN10/CV
voltage is disconnected from the RF5/AN10/CV
CVROE
RSRC
RSRC
R/W-0
to 0.667 CV
to 0.75 CV
RSRC
(1)
REF
REF
PIC18F6525/6621/8525/8621
REF
REF
) + (CVR3:CVR0/32) • (CV
+ and
Range Selection bit
R/W-0
CVRR
Source Selection bit
Output Enable bit
REF
W = Writable bit
‘1’ = Bit is set
RSRC
RSRC
RSRC
Value Selection bits (0 ≤ VR3:VR0 ≤ 15)
, with CV
, with CV
)
CVRSS
R/W-0
RSRC
RSRC
22.1
The comparator voltage reference can output 16
distinct voltage levels for each range. The equations
used to calculate the output of the comparator voltage
reference are as follows:
The settling time of the comparator voltage reference
must be considered when changing the CV
(Section 27.0 “Electrical Characteristics”).
RSRC
= V
= AV
RSRC
If CVRR = 1:
CV
If CVRR = 0:
CV
(1)
REF
REF
REF
/32 step size (high range)
DD
/24 step size (low range)
Configuring the Comparator
Voltage Reference
R/W-0
CVR3
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
RSRC
+ – V
= (CV
– AV
= (CVR<3:0>/24) x CV
)
REF
SS
RSRC
REF
-
REF
R/W-0
CVR2
x 1/4) + (CVR<3:0>/32) x CV
pin
pin
x = Bit is unknown
R/W-0
CVR1
RSRC
DS39612B-page 249
REF
R/W-0
CVR0
output
RSRC
bit 0