PIC18F258 Datasheet, PDF (258/384 Pages) Microchip Technology – High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN

PIC18FXX8
FIGURE 23-2:
LOW VOLTAGE DETECT (LVD) BLOCK DIAGRAM
VDD
LVDIN
LVD3:LVD0
LVDCON
Register
LVDIF
LVDEN
Internally Generated
Reference Voltage
The LVD module has an additional feature that allows
the user to supply the trip voltage to the module from
an external source. This mode is enabled when bits
LVDL3:LVDL0 are set to ‘1111’. In this state, the com-
parator input is multiplexed from the external input pin
LVDIN to one input of the comparator (Figure 23-3).
The other input is connected to the internally gener-
ated voltage reference (parameter D423 in
Section 27.2). This gives users flexibility, because it
allows them to configure the Low Voltage Detect inter-
rupt to occur at any voltage in the valid operating
range.
FIGURE 23-3:
LOW VOLTAGE DETECT (LVD) WITH EXTERNAL INPUT BLOCK DIAGRAM
VDD
VDD
LVD3:LVD0
LVDCON
Register
Externally Generated
Trip Point
LVDIN
LVDEN
LVD
VxEN
BODEN
EN
BGAP
DS41159B-page 256
Preliminary
 2002 Microchip Technology Inc.