Datasheet

PIC18F1230/1330

DS39758D-page 188  2009 Microchip Technology Inc.

The module is enabled by setting the LVDEN bit. Each

time that the LVD module is enabled, the circuitry

requires some time to stabilize. The IRVST bit is a

read-only bit and is used to indicate when the circuit is

stable. The module can only generate an interrupt after

the circuit is stable and IRVST is set.

19.1 Operation

When the LVD module is enabled, a comparator uses

an internally generated reference voltage as the set

point. The set point is compared with the trip point,

where each node in the resistor divider represents a

trip point voltage. The “trip point” voltage is the voltage

level at which the device detects a low-voltage event

depending on the configuration of the module. When

the supply voltage is equal to the trip point, the voltage

tapped off of the resistor array is equal to the internal

reference voltage generated by the voltage reference

module. The comparator then generates an interrupt

signal by setting the LVDIF bit.

The trip point voltage is software programmable to any 1 of

15 values. The trip point is selected by programming the

LVDL3:LVDL0 bits (LVDCON<3:0>).

FIGURE 19-1: LVD MODULE BLOCK DIAGRAM

Set

VDD

16-to-1 MUX

LVDEN

LVDCON

LVDL3:LVDL0

LVDIF

LVDEN

BORENx

Internal Voltage

Reference