PIC18C858-E/L Microchip Technology, PIC18C858-E/L Datasheet - Page 243

• Manufacturer Part Number: PIC18C858-E/L
• Description: IC MCU OTP 16KX16 CAN 84PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C858-E/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 68
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: OTP
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 84-PLCC
• For Use With: AC164310 - MODULE SKT FOR PM3 84PLCCDVA18XL840 - ADAPTER DEVICE ICE 84PLCCAC174012 - MODULE SKT PROMATEII 84PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: PIC18C858E/L

20.0
The Comparator Voltage Reference is a 16-tap resistor
ladder network that provides a selectable voltage refer-
ence. The resistor ladder is segmented to provide two
ranges of CV
tion to conserve power when the reference is not being
used. The CVRCON register controls the operation of
the reference as shown in Register 20-1. The block dia-
gram is given in Figure 20-1.
The comparator reference supply voltage can come
from either V
V
comparator reference supply voltage is controlled by
the CVRSS bit.
REGISTER 20-1: VRCON REGISTER
REF
2000 Microchip Technology Inc.
- that are multiplexed with RA3 and RA2. The
COMPARATOR VOLTAGE
REFERENCE MODULE
REF
DD
bit 7
bit 6
bit 5
bit 4
bit 3-0
or V
values and has a power-down func-
SS
bit 7
VREN: Comparator Voltage Reference Enable
1 = CV
0 = CV
VROE: Comparator V
1 = CV
0 = CV
VRR: Comparator V
1 = 0.00 CV
0 = 0.25 CV
VRSS: Comparator V
1 = Comparator reference source CV
0 = Comparator reference source CV
VR3:VR0: Comparator V
When VRR = 1:
CV
When VRR = 0:
CV
Legend:
R = Readable bit
- n = Value at POR
, or the external V
R/W-0
VREN
REF
REF
= (VR<3:0>/ 24) (CV
= 1/4 (CV
REF
REF
REF
REF
circuit powered on
circuit powered down
voltage level is also output on the RF5/AN10/CV
voltage is disconnected from the RF5/AN10/CV
RSRC
RSRC
R/W-0
VROE
RSRC
to 0.75 CV
to 0.75 CV
Advanced Information
REF
REF
REF
REF
) + (VR3:VR0/ 32) (CV
Range Selection
+ and
REF
Source Selection
Output Enable
R/W-0
’1’ = Bit is set
VRR
W = Writable bit
Value Selection 0
RSRC
RSRC
RSRC
, with CV
, with CV
)
RSRC
RSRC
R/W-0
VRSS
20.1
The Comparator Voltage Reference can output 16 dis-
tinct voltage levels for each range. The equations used
to calculate the output of the Comparator Voltage Ref-
erence are as follows:
The settling time of the Comparator Voltage Reference
must be considered when changing the CV
(Section 25.0).
RSRC
RSRC
= V
= V
If CVRR = 1:
CV
If CVRR = 0:
CV
REF
DD
REF
REF
RSRC
/24 step size
/32 step size
VR3:VR0
Configuring the Comparator Voltage
Reference
U = Unimplemented bit, read as ‘0’
’0’ = Bit is cleared
-V
+-V
= (CV
R/W-0
= (CV
SS
VR3
)
REF
R
DD
-
<3:0>/24) x CV
REF
x 1/4) + (CV
REF
15
R/W-0
VR2
pin
PIC18CXX8
pin
x = Bit is unknown
R
RSRC
R/W-0
<3:0>/32) x CV
VR1
DS30475A-page 243
REF
R/W-0
VR0
output
RSRC
bit 0