PIC18F23K22 Datasheet, PDF (343/492 Pages) Microchip Technology – 28/40/44-Pin, Low-Power, High-Performance Microcontrollers with nanoWatt XLP Technology

PIC18(L)F2X/4XK22
23.0 HIGH/LOW-VOLTAGE DETECT
(HLVD)
The PIC18(L)F2X/4XK22 devices have a High/Low-Volt-
age Detect module (HLVD). This is a programmable cir-
cuit that sets both a device voltage trip point and the
direction of change from that point. If the device experi-
ences an excursion past the trip point in that direction, an
interrupt flag is set. If the interrupt is enabled, the pro-
gram execution branches to the interrupt vector address
and the software responds 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 module’s block diagram is shown in Figure 23-1.
REGISTER 23-1: HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER
R/W-0
VDIRMAG
bit 7
R-0
BGVST
R-0
IRVST
R/W-0
HLVDEN
R/W-0
R/W-1
R/W-0
HLVDL<3:0>
R/W-1
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3-0
Note 1:
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>)
BGVST: Band Gap Reference Voltages Stable Status Flag bit
1 = Internal band gap voltage references are stable
0 = Internal band gap voltage reference is not stable
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
HLVDEN: High/Low-Voltage Detect Power Enable bit
1 = HLVD enabled
0 = HLVD disabled
HLVDL<3:0>: Voltage Detection Level bits⁽¹⁾
1111 = External analog input is used (input comes from the HLVDIN pin)
1110 = Maximum setting
.
.
.
0000 = Minimum setting
See Table 27-4 for specifications.
 2010 Microchip Technology Inc.
Preliminary
DS41412B-page 343