![](http://datasheet.mmic.net.cn/Nuvoton-Technology-Corporation-of-America/W83627UHG_datasheet_99877/W83627UHG_62.png)
W83627UHG
reset by reading all the interrupt status registers, or subsequent events do not generate interrupts.
This is illustrated in the figure above.
7.7.2 OVT# Interrupt Mode
The SMI#/OVT# pin 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 OVT# mode, it can monitor
temperatures, and it is enabled or disabled for SYSTIN and CPUTIN by Bank0 Index 18h, bit 6; and
Bank0, Index 4Ch, bit 3.
The OVT# pin has two interrupt modes, comparator and interrupt. The modes are illustrated in this
figure.
THYST
**
*Interrupt Reset when Temperature sensor registers are read
OVT#
*
(Comparator Mode; default)
(Interrupt Mode)
To
Figure 7-21 OVT# Modes of Temperature Inputs
If Bank0, Index 18h, bit 4, and Bank1 Index 52h, bit1 are set to zero, the OVT# pin is in comparator
mode. In comparator mode, the OVT# pin can create an interrupt once the current temperature
exceeds TO and continues to create interrupts until the temperature falls below THYST. The OVT# pin is
asserted once the temperature has exceeded TO and has not yet fallen below THYST.
If Bank0, Index 18h, bit 4, and Bank1 Index 52h, bit1 are set to one, the OVT# pin is in interrupt mode.
In interrupt mode, the OVT# pin can create an interrupt once the current temperature rises above TO
or when the temperature falls below THYST. Once the temperature rises above TO, however, and
generates an interrupt, this mode does not generate additional interrupts, even if the temperature
remains above TO, until the temperature falls below THYST. This interrupt must be reset by reading all
the interrupt status registers. The OVT# pin is asserted when an interrupt is generated and remains
asserted until the interrupt is reset.
7.7.3 Caseopen Detection
The purpose of Caseopen function is used to detect whether the computer case has been opened and
possibly tampered with. This feature must function even when there is no 5VSB power. Consequently,
the power source for the circuit is from either Pin 74 (VBAT) or Pin 61 (5VSB). 5VSB is the default
Publication Release Date: March 24, 2008
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Revision 1.44