Datasheet
2010 Microchip Technology Inc. DS39635C-page 275
PIC18F6310/6410/8310/8410
23.0 HIGH/LOW-VOLTAGE
DETECT (HLVD)
PIC18F6310/6410/8310/8410 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 inter-
rupt 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.
The High/Low-Voltage Detect Control register
(Register 23-1) 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 23-1.
REGISTER 23-1: HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER
R/W-0 U-0 R-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1
VDIRMAG — IRVST HLVDEN HLVDL3
(1)
HLVDL2
(1)
HLVDL1
(1)
HLVDL0
(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 VDIRMAG: Voltage Direction Magnitude Select bit
1 = Event occurs when voltage equals or exceeds trip point (HLVDL<3:0>)
0 = Event occurs when voltage equals or falls below trip point (HLVDL<3:0>)
bit 6 Unimplemented: Read as ‘0’
bit 5 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
range and the HLVD interrupt should not be enabled
bit 4 HLVDEN: High/Low-Voltage Detect Power Enable bit
1 = HLVD is enabled
0 = HLVD is disabled
bit 3-0 HLVDL<3:0>: Voltage Detection Limit bits
(1)
1110 = Maximum setting
•
•
•
0001 = Minimum setting
Note 1: HLVDL<3:0> modes that result in a trip point, below the valid operating voltage of the device, are not
tested.