W83637HF Datasheet, PDF (40/149 Pages) Winbond – LPC I/O

W83637HF
6.6.3 The W83637HF temperature sensor 1(SYSTIN) SMI# interrupt has two modes
(1) Comparator Interrupt Mode
Setting the T_HYST (Temperature Hysteresis) limit to 127°C will set temperature sensor 1 SMI# to
the Comparator Interrupt Mode. Temperature exceeds T_O (Over Temperature) Limit causes an
interrupt and this interrupt will be reset by reading all the Interrupt Status Register. Once an
interrupt event has occurred by exceeding T_O, then reset, if the temperature remains above the
T_O, the interrupt will occur again when the next conversion has completed. If an interrupt event
has occurred by exceeding T_O and not reset, the interrupts will not occur again. The interrupts will
continue to occur in this manner until the temperature goes below T_O. (Figure 6.11)
Setting the T_HYST lower than T_O will set temperature sensor 1 SMI# to the Interrupt Mode. The following
are two kinds of interrupt modes, which are selected by Index 4Ch bit5:
(2) Two-Times Interrupt Mode
Temperature exceeding T_O causes an interrupt and then temperature going below T_HYST will also
cause an interrupt if the previous interrupt has been reset by reading all the interrupt Status
Register. Once an interrupt event has occurred by exceeding T_O, then reset, if the temperature
remains above the T_HYST, the interrupt will not occur. (Figure 6.12)
(3) One-Time Interrupt Mode
Temperature exceeding T_O causes an interrupt and then temperature going below T_HYST will not
cause an interrupt. Once an interrupt event has occurred by exceeding T_O, then going below
T_HYST, an interrupt will not occur again until the temperature exceeding T_O. (Figure .6.13)
T_HYST
127'C
T_OI
T_OI
T_HYST
SMI#
*
*
*
SMI#
*
*
*
*
*Interrupt Reset when Interrupt Status Registers are read
Figure 6.11
Figure 6.12
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Publication Release Date: June 25, 2003
Revision 1.3