Chapter 9
Low-Voltage Inhibit (LVI)
9.1 Introduction
The low-voltage inhibit (LVI) module is provided as a system protection mechanism to prevent the MCU
from operating below a certain operating supply voltage level. The module has several configuration
options to allow functionality to be tailored to different system level demands.
The configuration registers (see
contain
control bits for this module.
9.2 Features
Features of the LVI module include:
• Programmable LVI reset
• Selectable LVI trip voltage
• Programmable stop mode operation
9.3 Functional Description
shows the structure of the LVI module. LVISTOP, LVIPWRD, LVITRIP, and LVIRSTD are user
selectable options found in the configuration register.
V
DD
STOP INSTRUCTION
LVISTOP
FROM CONFIGURATION REGISTER
FROM CONFIGURATION REGISTER
LVIRSTD
LVIPWRD
FROM CONFIGURATION REGISTER
LOW V
DD
DETECTOR
0 IF V
DD
> V
TRIPR
1 IF V
DD
≤
V
TRIPF
LVIOUT
LVITRIP
FROM CONFIGURATION REGISTER
LVI RESET
Figure 9-1. LVI Module Block Diagram
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 5
Freescale Semiconductor
93
FREESCALE [ FREESCALE SEMICONDUCTOR, INC ]
