PIC18F2682-I/PT MICROCHIP [Microchip Technology], PIC18F2682-I/PT Datasheet - Page 269

• Manufacturer Part Number: PIC18F2682-I/PT
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

22.0
PIC18F2682/2685/4682/4685 devices have a High/
Low-Voltage Detect module (HLVD). This is a
programmable circuit that allows the user to specify
both a device voltage trip point and the direction of
change from that point. If the device experiences an
excursion past the trip point in that direction, an
interrupt flag is set. If the interrupt is enabled, the
program execution will branch to the interrupt vector
address and the software can then respond to the
interrupt.
REGISTER 22-1:
© 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: HLVDL3:HLVDL0 modes that result in a trip point below the valid operating voltage of the device are not tested.
VDIRMAG
R/W-0
HIGH/LOW-VOLTAGE
DETECT (HLVD)
VDIRMAG: Voltage Direction Magnitude Select bit
1 = Event occurs when voltage equals or exceeds trip point (HLVDL3:HLDVL0)
0 = Event occurs when voltage equals or falls below trip point (HLVDL3:HLVDL0)
Unimplemented: Read as ‘0’
IRVST: Internal Reference Voltage Stable Flag bit
1 = Indicates that the voltage detect logic will generate the interrupt flag at the specified voltage range
0 = Indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage
HLVDEN: High/Low-Voltage Detect Power Enable bit
1 = HLVD enabled
0 = HLVD disabled
HLVDL3:HLVDL0: High/Low-Voltage Detection Limit bits
1111 = External analog input is used (input comes from the HLVDIN pin)
1110 = 4.48V-4.69V
1101 = 4.23V-4.43V
1100 = 4.01V-4.20V
1011 = 3.81V-3.99V
1010 = 3.63V-3.80V
1001 = 3.46V-3.63V
1000 = 3.31V-3.47V
0111 = 3.05V-3.19V
0110 = 2.82V-2.95V
0101 = 2.72V-2.85V
0100 = 2.54V-2.66V
0011 = 2.38V-2.49V
0010 = 2.31V-2.42V
0001 = 2.18V-2.28V
0000 = 2.12V-2.22V
range and the HLVD interrupt should not be enabled
U-0
—
HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER
W = Writable bit
‘1’ = Bit is set
IRVST
R-0
PIC18F2682/2685/4682/4685
HLVDEN
R/W-0
Preliminary
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
HLVDL3
R/W-0
The
(Register 22-1) completely controls the operation of the
HLVD module. This allows the circuitry to be “turned
off” by the user under software control, which
minimizes the current consumption for the device.
The block diagram for the HLVD module is shown in
Figure 22-1.
(1)
High/Low-Voltage
(1)
HLVDL2
R/W-1
(1)
x = Bit is unknown
Detect
HLVDL1
R/W-0
DS39761B-page 267
(1)
Control
HLVDL0
R/W-1
register
bit 0
(1)