W83627DHG Datasheet, PDF (62/268 Pages) Winbond – WINBOND LPC I/O

W83627DHG
7.7 Interrupt Detection
7.7.1 SMI# Interrupt Mode
The SMI#/OVT# pin (pin 5) is a multi-function pin. It can be in SMI# mode or in OVT# mode by setting
Configuration Register CR[29h], bit 6 to one or zero, respectively. In SMI# mode, it can monitor
voltages, fan counts, or temperatures.
7.7.1.1. Voltage SMI# Mode
The SMI# pin can create an interrupt if a voltage exceeds a specified high limit or falls below a specified
low limit. This interrupt must be reset by reading all the interrupt status registers, or subsequent events
do not generate interrupts. This mode is illustrated in the following figure.
High limit
Low limit
Fan Count limit
SMI#
*
*
*
*
SMI#
*
*
*Interrupt Reset when Interrupt Status Registers are read
7.7.1.2. Fan SMI# Mode
The SMI# pin can create an interrupt if a fan count crosses a specified fan limit (rises above it or falls
below it). This interrupt must be reset by reading all the interrupt status registers, or subsequent events
do not generate interrupts. This mode is illustrated in the figure above.
7.7.1.3. Temperature SMI# Mode
The SMI# pin can create interrupts that depend on the temperatures measured by SYSTIN, CPUTIN,
and AUXTIN. These interrupts are divided into two parts, one for SYSTIN and the other for CPUTIN /
AUXTIN.
7.7.1.3.1. Temperature Sensor 1(SYSTIN) SMI# Interrupt
The SMI# pin has three interrupt modes with SYSTIN.
(1) Comparator Interrupt Mode
This mode is enabled by setting T_HYST (Temperature Hysteresis) to 127°C.
In this mode, the SMI# pin can create an interrupt as long as the current temperature exceeds T_O
(Over Temperature). This interrupt can be reset by reading all the interrupt status registers, or
subsequent events do not generate interrupts. If the interrupt is reset, the SMI# pin continues to
create interrupts until the temperature goes below T_O. This is illustrated in the figure below.
Publication Release Date: Aug, 22, 2007
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Version 1.4