PIC18CXX2
17.2.1 REFERENCE VOLTAGE SET POINT
17.3
Operation During Sleep
The Internal Reference Voltage of the LVD module may
be used by other internal circuitry (the programmable
brown-out reset). If these circuits are disabled (lower
current consumption), the reference voltage circuit
requires a time to become stable before a low voltage
condition can be reliably detected. This time is invariant
of system clock speed. This start-up time is specified in
electrical specification parameter #36. The low-voltage
interrupt flag will not be enabled until a stable reference
voltage is reached. Refer to the waveform in Figure 17-
3.
When enabled, the LVD circuitry continues to operate
during sleep. If the device voltage crosses the trip point,
the LVDIF bit will be set and the device will wake-up
from sleep. Device execution will continue from the
interrupt vector address if interrupts have been globally
enabled.
17.4
Effects of a Reset
A device reset forces all registers to their reset state.
This forces the LVD module to be turned off.
17.2.2 CURRENT CONSUMPTION
When the module is enabled, the LVD comparator and
voltage divider are enabled and will consume static cur-
rent. The voltage divider can be tapped from multiple
places in the resistor array. Total current consumption,
when enabled, is specified in electrical specification
parameter #D022B.
7/99 Microchip Technology Inc.
Preliminary
DS39026B-page 179
MICROCHIP [ MICROCHIP ]
